交通毕业设计外文及翻译
毕业设计中英文翻译【范本模板】
英文The road (highway)The road is one kind of linear construction used for travel。
It is made of the roadbed，the road surface, the bridge, the culvert and the tunnel. In addition, it also has the crossing of lines, the protective project and the traffic engineering and the route facility。
The roadbed is the base of road surface, road shoulder，side slope, side ditch foundations. It is stone material structure, which is designed according to route's plane position .The roadbed, as the base of travel, must guarantee that it has the enough intensity and the stability that can prevent the water and other natural disaster from corroding.The road surface is the surface of road. It is single or complex structure built with mixture。
The road surface require being smooth，having enough intensity，good stability and anti—slippery function. The quality of road surface directly affects the safe, comfort and the traffic。
地铁隧道毕业设计外文翻译
外 文 翻 译
年 级: 2005 级 学 号:20057375 姓 名: 黄 磊 专 业:铁道工程 指导老师: 钟新樵
2009 年 6 月
西南交通大学本科毕业设计(论文)外文翻译
第1页
【原文】
A study on underground tunnel ventilation for piston effects influenced by draught relief shaft in subway system
西南交通大学本科毕业设计(论文)外文翻译
第3页
Cm
For air inflow,
AvVv Qb AV Qc
(1)
Cm K i
For air outflow,
ቤተ መጻሕፍቲ ባይዱAv A
Cp Cps
(2)
Cm K o where A Av Cm tunnel area (m2) relief shaft area (m2)
CΔHi Ki, Ko Qb, Qc
entrance loss at the bottom of relief shaft empirical constants for inflow and outflow air flow volume rate through relief shaft and upstream(or downstream) (m3/s)
Chi-Ji Lin, Yew Khoy Chuah, Chia-Wei Liu
Abstract
This is a study on underground tunnel ventilation for piston effects influenced by draught relief shaft. Field measurements of transient air movement in the draught relief shaft for a typical Taipei underground subway station were taken under winter and summer conditions. It has been found that the air in the draught relief shaft has a maximum of 2 m/s, and on average lies between 0.7 and 1.1 m/s. This study defines an index ηPE, for evaluating the efficiency of tunnel ventilation by piston effects. This index can be used to analyze the piston effects due to different shaft length and sectional area. The measurement results show that the train piston effects are effective only for certain shaft length and operating conditions. This study also used the authoritative SES computer program to simulate the piston effects. The simulation results for inflow and outflow velocity profile are almost consistent with the measurement. The shaft sectional area was also investigated and has been found that a larger sectional area resulted in larger volume flow rate, but the percentage increase is less than the percentage increase in the sectional area. This will result in smaller air velocity in shaft and less effective air exchange between the tunnel and the outside ambient. It also has been found that length of the draught relief shaft is more so an important design parameter for efficient air exchange by piston effects for underground subway systems. It is suggested here that the design of the draught relief shaft has to consider requirements including ηPE, pressure loss and noise.
西南交通大学毕业设计英语文献翻译年
西南交通大学毕业设计英语文献翻译年级： 2003级学号： 2003XXXX姓名： XX XX专业： XXXX运输指导老师： XX XX2007年XX月XX日Britain railway(英文)Railway safety（小四times new roman，1.5倍行距）Already rail is one of the safest forms of travel and the long term improvement in rail safety is continuing. But the Chief Inspector of Railways has warned that some operators have tried to avoid taking measures to improve rail safety standards, or worse still, to reduce them. It is vital to ensure that there is no erosion of safety standards in the privatised railway. Existing standards of health and safety must be maintained and, where necessary, improved. Operators must not put commercial considerations ahead of safety.The Health and Safety Commission, together with its operational arm the Health and Safety Executive, which includes the Railway Inspectorate, is the independent regulatory body responsible for railway safety. The Railway Inspectorate has comprehensive powers to enforce the wide-ranging duties of the Health and Safety at Work etc. Act 1974 and associated Regulations.A new safety regime for the privatised railway was put in place in 1994. It reflects Railtrack's and train operating companies' obligations under the HSWA to operate safely.Railtrack has responsibilities for both setting and enforcing safety standards. The single most important element in the regime is a requirement for each operator to prepare, and obtain acceptance of, a 'safety case'- a detailed document describing the operator's risk assessments and safety management systems. The regime also gave Railtrack wideranging responsibilities for both setting and enforcing safety standards.We are determined to ensure, as part of improving the railways in the interests of passengers, that safety is not compromised. The Health and Safety Commission fully shares this resolve. It has recently gone out to formal consultation on draft regulations to oblige the privatised industry to replace or modify Mark 1 (ie slam-door) rolling stock by 2003 and to install train protection (which would apply the brake automatically in danger situations) on all trains and at all key signals by 2004. Mark 1 rolling stock has been criticised because of how it performs in certain types of accidents. The Commission has recommended that all Mark 1 rolling stock be英国铁路（中文翻译，居中）正文，小四宋体，1.5倍行距，如有多级标题，标题写法参照毕业设计正文格式铁路可以说是最安全的出行方式之一，并且铁路安全性的长期改善是持续的。
道路毕业设计英文翻译
道路毕业设计英文翻译Road Graduation Design: English TranslationIntroductionRoads play a crucial role in our daily lives, connecting people, places, and goods. As a civil engineering student, I had the opportunity to work on a graduation design project focused on road infrastructure. In this article, I will share the key aspects of my project and discuss the importance of road design and its impact on society.The Significance of Road DesignRoad design is a multidisciplinary field that encompasses various aspects, including engineering, urban planning, and environmental considerations. A well-designed road network ensures efficient transportation, reduces traffic congestion, and enhances road safety. Moreover, it contributes to economic growth by facilitating the movement of goods and services.Designing Sustainable RoadsSustainability is a crucial factor in road design. As our society becomes more conscious of environmental issues, it is essential to consider the environmental impact of road construction and operation. During my graduation project, I focused on incorporating sustainable practices into road design.One aspect of sustainable road design is the use of environmentally friendly materials. For example, I explored the possibility of using recycled asphalt pavement (RAP) in road construction. RAP not only reduces the demand forvirgin materials but also minimizes waste and energy consumption. Additionally, I studied the implementation of green infrastructure along roads. Green infrastructure refers to the integration of vegetation and natural elements into the road design. This approach helps mitigate the urban heat island effect, improves air quality, and enhances the aesthetic appeal of the road network. Innovative Technologies in Road DesignAdvancements in technology have revolutionized road design and construction. During my project, I explored the application of various innovative technologies that can improve road performance and durability.One such technology is the use of intelligent transportation systems (ITS). ITS utilizes sensors, cameras, and communication networks to monitor traffic conditions, manage congestion, and enhance road safety. Integrating ITS into road design helps optimize traffic flow, reduces travel time, and minimizes accidents.Another technology I investigated was the use of 3D modeling and visualization. By creating virtual models of roads, engineers can better assess the design's feasibility, identify potential challenges, and make informed decisions. This approach improves the accuracy and efficiency of the design process.The Role of Public ParticipationRoad design is not solely a technical endeavor; it also involves the community and its needs. Public participation plays a vital role in ensuring that road projects meet the expectations and requirements of the people.During my graduation project, I conducted surveys and organized public consultations to gather feedback from the community. This input helped me understand the local context, identify concerns, and incorporate them into the road design. By involving the public, we can create roads that are more user-friendly, inclusive, and responsive to the community's needs.ConclusionRoad design is a complex and multifaceted discipline with significant implications for society. By focusing on sustainability, incorporating innovative technologies, and involving the public, we can create road networks that are efficient, environmentally friendly, and meet the needs of the community. As a civil engineering student, my graduation project allowed me to gain valuable insights into the world of road design and its potential to shape our future.。
道路工程毕业设计外文翻译---高速公路设计与施工
原文Highway Design and Construction: The Innovation Challenge Author: Robert E. Skinner Jr.Innovations and advances in research are changing the way highways are built in America.The Egyptians were pouring concrete in 2500 BC, and the Romans used it to construct the Pantheon and the Colosseum. By the mid-1800s, Europeans were building bridges with concrete, and the first “modern” concrete highway pavements appear ed in the latter part of the 19th century. Naturally occurring asphalts, which have been used for waterproofing for thousands of years, came into common use in road construction in the 1800s. The first iron bridge was constructed in 1774, but by the end of the 19th century steel had largely replaced iron in bridge construction. These materials—concrete, asphalt, and steel—are now the mainstays of highway and bridge construction throughout the world, as well as of most types of public works infrastructure. Concrete and steel, the most versatile of these materials, are used for bridges and other highway structures; concrete and asphalt are used for roadway pavements.Everyone is familiar with concrete, asphalt, and steel, and some of us have worked with them, perhaps on home improvement projects. This familiarity, coupled with the long history of their many uses, has led many otherwise technically savvy people to believe that these materials are well understood, that their performance can be easily and reliably predicted, and that the technical challenges in using them for highways were overcome long ago. However, such notions are largely incorrect and misleading.For example, consider concrete, which is a mixture of portland cement, sand, aggregate (gravel or crushed stone), and water. Its performance characteristics are determined by the proportions and characteristics of the components, as well as by how it is mixed and formed. The underlying chemical reactions of concrete are surprisingly complex, not completely understood, and vary with the type of stone. Steel may be added for tensile strength (reinforced concrete), and a variety of additives have been identified to improve the workabilityand performance of concrete in particular applications and conditions. Damage and deterioration to concrete can result from excessive loadings and environmental conditions, such as freeze-thaw cycles and chemical reactions with salts used for deicing._________________________Many factors contribute to theurgent need for innovation inhighway construction._________________________Concrete is the most heavily used substance in the world after water (Sedgwick, 1991). Worldwide, concrete construction annually consumes about 1.6 billion tons of cement, 10 billion tons of sand and crushed stone, and 1 billion tons of water (M.S. Kahn, 2007). Given transportation costs, there is a huge financial incentive to using local sources of stone, even if the properties of that stone are less than ideal. Thus concrete is not a homogenous material. In truth, an unlimited number of combinations and permutations are possible.Much the same can be said of asphalt—technically, asphaltic concrete—which is also a mixture of aggregate (gravel or crushed stone), sand, and cement (asphalt binder); economics promote the use of locally available materials; and the underlying chemistry is not well understood. The characteristics of asphalt binder, for instance, vary depending on the source of crude oil from which it is derived.The metallurgy of steel is probably better understood than the chemistry of either asphalt or concrete, but it too is a mixture with virtually limitless combinations. Strength, toughness, corrosion resistance, and weldability are some of the performance characteristics that vary with the type of steel alloy used and the intended applications.As uses evolve and economic conditions change, we have a continuing need for a more sophisticated understanding of these common materials. Even though they are “mature” products, there is still room for significant incremental improvements in their performance. Because fundamental knowledge is still wanting, there is also considerable potential for breakthroughs in their performance.Factors That Affect Highway ConstructionAll other things being equal, stronger, longer lasting, less costly highway materials are desirable and, given the quantities involved, there are plenty of incentives for innovation. In highway transportation, however, all other things are not equal. A number of other factors contribute to the urgent and continuing need for innovation.First, traffic volume and loadings continue to increase. Every day the U.S. highway network carries more traffic, including heavy trucks that were unimagined when the system wasoriginally conceived and constructed. The 47,000-mile interstate highway system today carries more traffic than the entire U.S. highway system carried in 1956 when the interstates were laid out. The U.S. Department of Transportation (DOT) estimates that in metropolitan areas the annual cost of traffic congestion for businesses and citizens is nearly $170 billion (PB Consult, Inc., 2007).On rural interstates, overall traffic more than doubled between 1970 and 2005; at the same time, the loadings on those highways increased six-fold, mainly due to the increase in the number of trucks and the number of miles they travel. (Truck traffic increased from about 5.7 percent of all vehicle-miles traveled on U.S. highways in 1965 to 7.5 percent in 2000 [FHWA, 2005]).Second, traffic disruptions must be kept to a minimum during construction. Our overstressed highway system is not very resilient. Thus disruptions of any sort, such as lane and roadway closings, especially in major metropolitan areas and on key Interstate routes, can cause massive traffic snarls. This means that repair and reconstruction operations must often be done at night, which introduces a variety of additional complexities and safety issues. Occasionally, heroic measures must be taken to keep traffic moving during construction. For example, during construction of the “Big Dig” in Boston, the elevated Central Artery was in continuous service while cut-cover tunnels were constructed directly below it.Third, environmental, community, and safety requirements have become more stringent. For many good reasons, expectations of what a highway should be, how it should operate, and how it should interact with the environment and adjacent communities are constantly evolving. Designs to promote safety, measures to mitigate a growing list of environmental impacts, and attention to aesthetics have fundamentally changed the scope of major highway projects in the United States. For example, on Maryland’s $2.4 billion Intercounty Connector project in suburban Washington, D.C., which is now under construction, environmental mitigation accounts for 15 percent of project costs, or about $15 million per mile (AASHTO, 2008). Fourth, costs continue to rise. Building and maintaining highways cost effectively is an ever-present goal of good engineering. But cost increases in highway construction have been extraordinary due in part to the expanded scope of highway projects and construction in demanding settings. In addition, the costs of the mainstay materials—portland cement, asphalt binder, and steel—have risen dramatically as the world, particularly China, has gone on a construction binge. The Federal Highway Administration’s cost indices for portland cement concrete pavement, asphalt pavement, and structural steel increased by 51 percent, 58 percent, and 70 percent respectively between 1995 and 2005 (FHWA, 2006).Fortunately, research and innovation in construction have never stopped, although they are not always sufficiently funded and they seem to fly beneath the radar of many scientists and engineers. Nevertheless, there have been great successes, which are cumulatively changing how highways are built in America.The Superpave Design SystemIn response to widespread concerns about premature failures of hot-mix asphalt pavements in the early 1980s, a well funded, congressionally mandated, crash research program was conducted to improve our understanding of asphalt pavements and their performance. The seven-year Strategic Highway Research Program (SHRP), which was managed by the National Research Council, developed a new system of standard specifications, test methods, andengineering practices for the selection of materials and the mix proportions for hot-mix asphalt pavement.The new system has improved matches between combinations of asphalt binder and crushed stone and the climatic and traffic conditions on specific highways. State departments of transportation (DOTs) spend more than $10 billion annually on these pavements, so even modest improvements in pavement durability and useful life can lead to substantial cost savings for agencies and time savings for motorists (TRB, 2001).SHRP rolled out the Superpave system in 1993, but it took years for individual states and their paving contractors to switch to the new system, which represents a significant departure, not only in design, but also in the procedures and equipment used for testing. Each state DOT had to be convinced that the benefits would outweigh the modest additional costs of Superpave mixes, as well as the time and effort to train its staff and acquire necessary equipment.A survey in 2005 showed that 50 state DOTs (including the District of Columbia and Puerto Rico) were using Superpave (Figure 1). The remaining two states indicated that they would be doing so by the end of 2006. Throughout the implementation period, researchers continued to refine the system (e.g., using recycled asphalt pavements in the mix design [TRB, 2005]).It may be years before the cost benefits of Superpave can be quantified. A 1997 study by the Te xas Transportation Institute projected that, when fully implemented, Superpave’s annualized net savings over 20 years would approach $1.8 billion annually—approximately $500 million in direct savings to the public and $1.3 billion to highway users (Little et al., 1997).Moreover, analyses by individual states and cities have found that Superpave has dramatically improved performance with little or no increase in cost. Superpave is not only an example of a successful research program. It also demonstrates that a vigorous, sustained technology-transfer effort is often required for innovation in a decentralized sector, such as highway transportation.Prefabricated ComponentsThe offsite manufacturing of steel and other components of reinforced concrete for bridges and tunnels is nothing new. But the need for reconstructing or replacing heavily used highway facilities has increased the use of prefabricated components in startling ways. In some cases components are manufactured thousands of miles from the job site; in others, they are manufactured immediately adjacent to the site. Either way, we are rethinking how design and construction can be integrated.When the Texas Department of Transportation needed to replace 113 bridge spans on an elevated interstate highway in Houston, it found that the existing columns were reusable, but the bent caps (the horizontal connections between columns) had to be replaced. As an alternative to the conventional, time-consuming, cast-in-place approach, researchers at the University of Texas devised new methods of installing precast concrete bents. In this project, the precast bents cut construction time from 18 months to slightly more than 3 months (TRB, 2001).As part of a massive project to replace the San Francisco-Oakland Bay Bridge, the California Department of Transportation and the Bay Area Toll Authority had to replace a 350-foot, 10-lane section of a viaduct on Yerba Buena Island. In this case, the contractor, C.C. Myers, prefabricated the section immediately adjacent to the existing viaduct. The entire bridge was then shut down for the 2007 Labor Day weekend, while the existing viaduct was demolished and the new 6,500-ton segment was “rolled” into place (Figure 2). The entire operation was accomplished 11 hours ahead of schedule (B. Kahn, 2007).Probably the most extensive and stunning collection of prefabricated applications on a single project was on the Central Artery/Tunnel Project (“Big Dig”) in Boston. For the Ted Williams Tunnel, a dozen 325-foot-long steel tunnel sections were constructed in Baltimore, shipped to Boston, floated into place, and then submerged. However, for the section of the tunnel that runs beneath the Four Points Channel, which is part of the I-90 extension, bridge restrictions made this approach infeasible. Instead, a huge casting basin was constructed adjacent to the channel where 30- to 50-ton concrete tunnel sections were manufactured The basin was flooded and the sections winched into position with cables and then submerged.An even more complicated process was used to build the extension tunnel under existing railroad tracks, which had poor underlying soil conditions. Concrete and steel boxes were built at one end of the tunnel, then gradually pushed into place through soil that had been frozen using a network of brine-filled pipes (Vanderwarker, 2001).Specialty Portland Cement ConcretesNew generations of specialty concretes have improved one or more aspects of performance and allow for greater flexibility in highway design and construction. High-performance concrete typically has compressive strengths of at least 10,000 psi. Today, ultra-high-performance concretes with formulations that include silica fume, quartz flour, water reducers, and steel or organic fibers have even greater durability and compressive strengths up to 30,000 psi. These new concretes can enable construction with thinner sections and longer spans (M.S. Kahn, 2007).Latex-modified concrete overlays have been used for many years to extend the life of existing, deteriorating concrete bridge decks by the Virginia DOT, which pioneered the use of very early strength latex-modified concretes for this application. In high-traffic situations, the added costs of the concrete have been more than offset by savings in traffic-control costs and fewer delays for drivers (Sprinkel, 2006).When the air temperature dips below 40， costly insulation techniques must be used when pouring concrete for highway projects. By using commercially available admixtures that depress the freezing point of water, the U.S. Cold-Weather Research and Engineering Laboratory has developed new concrete formulations that retain their strength and durability at temperatures as low as 23?F. Compared to insulation techniques, this innovation has significantly decreased construction costs and extended the construction season in cold weather regions (Korhonen, 2004).As useful as these and other specialty concretes are, nanotechnology and nanoengineering techniques, which are still in their infancy, have the potential to make even more dramatic improvements in theperformance and cost of concrete.Waste and Recycled MaterialsHighway construction has a long history of using industrial waste and by-product materials. The motivations of the construction industry were simple—to help dispose of materials that are otherwise difficult to manage and to reduce the initial costs of highway construction. The challenge has been to use these materials in ways that do not compromise critical performance properties and that do not introduce substances that are potenti-ally harmful to people or the environment. At the same time, as concerns about sustainability have become more prominent in public thinking, the incentives to use by-product materials have increased. In addition, because the reconstruction and resurfacing of highways create their own waste, recycling these construction materials makes economic and environmental sense.Research and demonstration projects have generated many successful uses of by-product and recycled materials in ways that simultaneously meet performance, environmental, and economic objectives. For example, “crumb rubber” from old tires is increasingly being used as an additive in certain hot-mix asphalt pavement designs, and a number of patents have been issued related to the production and design of crumb rubber or asphalt rubber pavements (CDOT, 2003; Epps, 1994).Several states, notably California and Arizona, use asphalt rubber hot mix as an overlay for distressed flexible and rigid pavements and as a means of reducing highway noise. Materials derived from discarded tires have also been successfully used as lightweight fill for highway embankments and backfill for retaining walls, as well as for asphalt-based sealers and membranes (Epps, 1994; TRB, 2001).Fly ash, a residue from coal-burning power plants, and silica fume, a residue from metal-producing furnaces, are increasingly being used as additives to portland cement concrete. Fly-ash concretes can reduce alkali-silica reactions that lead to the premature deterioration of concrete (Lane, 2001), and silica fume is a component of the ultra-high-performance concrete described above.After many years of experimentation and trials, reclaimed asphalt pavement (RAP) is now routinely used in virtually all 50 states as a substitute for aggregate and a portion of the asphalt binder in hot-mix asphalt, including Superpave mixes. The reclaimed material typically constitutes 25 to 50 percent of the “new” mix (TFHRC, 1998). The National Asphalt Pavement Association estimates that 90 percent of the asphalt pavement removed each year is recycled and that approximately 125 millions tons of RAP are produced, with an annual savings of $300 million (North Central Superpave Center, 2004).Visualization, Global Positioning Systems, and Other New Tools For more than 20 years, highway engineers have used two-dimensional, computer-aided drafting and design (CADD) systems to accelerate the design process and reduce costs. The benefits of CADD systems have derived essentially from automating the conventional design process, with engineers doing more or less what they had done before, although much faster and with greater flexibility.New generations of three- and four-dimensional systems are introducing new ways of designing roads, as well as building them (Figure 4). For example, three-dimensional visualization techniques are clearly useful for engineers. But, perhaps more importantly, they have improved the communication of potential designs to affected communities and public officials; in fact, they represent an entirely new design paradigm. Four-dimensional systems help engineers and contractors analyze the constructability of proposed designs well in advance of actual constructionGlobal positioning systems are being used in surveying/layout, in automated guidance systems for earth-moving equipment, and for monitoring quantities. Other innovations include in situ temperature sensors coupled with data storage, transmission, and processing devices that provide onsite information about the maturity and strength of concrete as it cures (Hannon, 2007; Hixson, 2006).ConclusionThe examples described above suggest the wide range of exciting innovations in the design and construction of highways. These innovations address materials, roadway and bridge designs, design and construction methods, road safety, and a variety of environmental, community, and aesthetic concerns. Looking to the future, however, challenges to the U.S. highway system will be even more daunting—accommodating more traffic and higher loadings; reducing traffic disruptions during construction; meeting more stringent environmental, community, and safety requirements; and continuing pressure to reduce costs. Addressing these challenges will require a commitment to innovation and the research that supports innovation.中文翻译高速公路设计与施工：创新的挑战作者：小罗伯特·E·斯金纳研究方式的创新和进步正在改变着美国公路建设的方式。
毕业设计外文翻译
AT89C51外文翻译DescriptionThe AT89C51 is a low-power, high-performance CMOS 8-bit microcomputer with 4K bytes of Flash Programmable and Erasable Read Only Memory (PEROM). The device is manufactured using Atmel’s high density nonvolatile memory technology and is compatible with the industry standard MCS-51™ instruction-set and pinout. The on-chip Flash allows the program memory to be reprogrammed in-system or by a conventional nonvolatile memory programmer. By combining a versatile 8-bit CPU with Flash on a monolithic chip, the Atmel A T89C51 is a powerful microcomputer which provides a highly flexible and cost effective solution to many embedded control applications.Features• Compatible with MCS-51™ Products• 4K Bytes of In-System Reprogrammable Flash Memory– Endurance: 1,000 Write/Erase Cycles• Fully Static Operation: 0 Hz to 24 MHz• Three-Level Program Memory Lock• 128 x 8-Bit Internal RAM• 32 Programmable I/O Lines• Two 16-Bit Timer/Counters• Six Interrupt Sources• Programmable Serial Channel• Low Power Idle and Power Down ModesThe AT89C51 provides the following standard features: 4K bytes of Flash,128 bytes of RAM, 32 I/O lines, two 16-bit timer/counters, a five vector two-level interrupt architecture, a full duplex serial port, on-chip oscillator and clock circuitry. In addition, the AT89C51 is designed with static logic for operation down to zero frequency and supports two software selectable power saving modes. The Idle Mode stops the CPU while allowing the RAM, timer/counters, serial port and interrupt system to continue functioning. The Power-down Mode saves the RAM contents but freezes the oscillator disabling all other chip functions until the next hardware reset.VCCSupply voltage.GNDGround.Port 0Port 0 is an 8-bit open-drain bi-directional I/O port. As an output port, each pin can sink eight TTL inputs. When 1s are written to port 0 pins, the pins can be used as high-impedance inputs.Port 0 may also be configured to be the multiplexed low-order address/data bus during accesses to external program and data memory. In this mode P0 has internal pullups. Port 0 also receives the code bytes during Flash programming, and outputs the code bytes during program verification. External pullups are required during program verification.Port 1Port 1 is an 8-bit bi-directional I/O port with internal pullups.The Port 1 output buffers can sink/source four TTL inputs.When 1s are written to Port 1 pins they are pulled high by the internal pullups and can be used as inputs. As inputs,Port 1 p ins that are externally being pulled low will source current (IIL) because of the internal pullups.Port 1 also receives the low-order address bytes during Flash programming and verification.Port 2Port 2 is an 8-bit bi-directional I/O port with internal pullups.The Port 2 output buffers can sink/source four TTL inputs.When 1s are written to Port 2 pins they are pulled high by the internal pullups and can be used as inputs. As inputs,Port 2 pins that are externally being pulled low will source current (IIL) because of the internal pullups. Port 2 emits the high-order address byte during fetches from external program memory and during accesses to external data memory that use 16-bit addresses (MOVX @DPTR). In this application, it uses strong internal pullups when emitting 1s. During accesses to external data memory that use 8-bit addresses (MOVX @ RI), Port 2 emits the contents of the P2 Special Function Register. Port 2 also receives the high-order address bits and some control signals during Flash programming and verification.Port 3Port 3 is an 8-bit bi-directional I/O port with internal pullups. The Port 3 output buffers can sink/source four TTL inputs.When 1s are written to Port 3 pins they arepulled high by the internal pullups and can be used as inputs. As inputs,Port 3 pins that are externally being pulled low will source current (IIL) because of the pullups. Port 3 also serves the functions of various special features of the AT89C51 as listed below:Port 3 also receives some control signals for Flash programming and verification. RSTReset input. A high on this pin for two machine cycles while the oscillator is running resets the device.ALE/PROGAddress Latch Enable output pulse for latching the low byte of the address during accesses to external memory. This pin is also the program pulse input (PROG) during Flash programming. In normal operation ALE is emitted at a constant rate of 1/6 the oscillator frequency, and may be used for external timing or clocking purposes. Note, however, that one ALE pulse is skipped during each access to external Data Memory.If desired, ALE operation can be disabled by setting bit 0 of SFR location 8EH. With the bit set, ALE is active only during a MOVX or MOVC instruction. Otherwise, the pin is weakly pulled high. Setting the ALE-disable bit has no effect if the microcontroller is in external execution mode.PSENProgram Store Enable is the read strobe to external program memory. When the AT89C51 is executing code from external program memory, PSEN is activated twice each machine cycle, except that two PSEN activations are skipped during each access to external data memory.EA/VPPExternal Access Enable. EA must be strapped to GND in order to enable the device to fetch code from external program memory locations starting at 0000H up toFFFFH.Note, however, that if lock bit 1 is programmed, EA will be internally latched on reset. EA should be strapped to VCC for internal program executions.This pin also receives the 12-volt programming enable voltage (VPP) during Flash programming, for parts that require 12-volt VPP.XTAL1Input to the inverting oscillator amplifier and input to the internal clock operating circuit.XTAL2Output from the inverting oscillator amplifier.Oscillator CharacteristicsXTAL1 and XTAL2 are the input and output, respectively,of an inverting amplifier which can be configured for use as an on-chip oscillator, as shown in Figure 1. Either a quartz crystal or ceramic resonator may be used. To drive the device from an external clock source, XTAL2 should be left unconnected while XTAL1 is driven as shown in Figure 2.There are no requirements on the duty cycle of the external clock signal, since the input to the internal clocking circuitry is through a divide-by-two flip-flop, but minimum and maximum voltage high and low time specifications must be observed.Idle ModeIn idle mode, the CPU puts itself to sleep while all the on-chip peripherals remain active. The mode is invoked by software. The content of the on-chip RAM and all the special functions registers remain unchanged during this mode. The idle mode can be terminated by any enabled interrupt or by a hardware reset. It should be noted that when idle is terminated by a hard ware reset, the device normally resumes program execution, from where it left off, up to two machine cycles before the internal reset algorithm takes control. On-chip hardware inhibits access to internal RAM in this event, but access to the port pins is not inhibited. To eliminate the possibility of an unexpected write to a port pin when Idle is terminated by reset, the instruction following the one that invokes Idle should not be one that writes to a port pin or to external memory.Figure 1. Oscillator ConnectionsNote: C1, C2 = 30 pF ± 10 pF for Crystals= 40 pF ± 10 pF for Ceramic ResonatorsFigure 2. External Clock Drive ConfigurationPower-down ModeIn the power-down mode, the oscillator is stopped, and the instruction that invokes power-down is the last instruction executed. The on-chip RAM and Special Function Registers retain their values until the power-down mode is terminated. The only exit from power-down is a hardware reset. Reset redefines the SFRs but does not change the on-chip RAM. The reset should not be activated before VCC is restored to its normal operating level and must be held active long enough to allow the oscillator to restart and stabilize.Program Memory Lock BitsOn the chip are three lock bits which can be left unprogrammed (U) or can be programmed (P) to obtain the additional features listed in the table below.When lock bit 1 is programmed, the logic level at the EA pin is sampled and latched during reset.If the device is powered up without a reset, the latch initializes to a random value, and holds that value until reset is activated. It is necessary that the latched value of EA be in agreement with the current logic level at that pin in order for the device to function properly.Programming the FlashThe AT89C51 is normally shipped with the on-chip Flash memory array in the erased state (that is, contents = FFH)and ready to be programmed. The programming interface accepts either a high-voltage (12-volt) or a low-voltage (VCC) program enable signal. The low-voltage programming mode provides a convenient way to program the AT89C51 inside t he user’s system, while the high-voltage programming mode is compatible with conventional thirdparty Flash or EPROM programmers.The AT89C51 is shipped with either the high-voltage or low-voltage programming mode enabled. The respective top-side marking and device signature codes are listed in the following table.The AT89C51 code memory array is programmed byte-by-byte in either programming mode. To program any non-blank byte in the on-chip Flash Memory, the entire memory must be erased using the Chip Erase Mode. Programming Algorithm: Before programming the A T89C51, the address, data and control signals should be set up according to the Flash programming mode table and Figures 3 and 4. To program the AT89C51, take the following steps.1. Input the desired memory location on the address lines.2. Input the appropriate data byte on the data lines.3. Activate the correct combination of control signals.4. Raise EA/VPP to 12V for the high-voltage programming mode.5. Pulse ALE/PROG once to program a byte in the Flash array or the lock bits. The byte-write cycle is self-timedand typically takes no more than 1.5 ms. Repeat steps 1 through 5, changing the address and data for the entire array or until the end of the object file is reached.Data Polling: The AT89C51 features Data Polling to indicate the end of a write cycle. During a write cycle, anattempted read of the last byte written will result in the complement of the written datum on PO.7. Once the write cycle has been completed, true data are valid on all outputs, and the next cycle may begin. Data Polling may begin any time after a write cycle has been initiated.Ready/Busy: The progress of byte programming can also be monitored by the RDY/BSY output signal. P3.4 is pulled low after ALE goes high during programming to indicate BUSY. P3.4 is pulled high again when programming is done to indicate READY.Program V erify: If lock bits LB1 and LB2 have not been programmed, the programmed code data can be read back via the address and data lines for verificatio n. The lock bits cannot be verified directly. V erification of the lock bits is achieved by observing that their features are enabled.Chip Erase: The entire Flash array is erased electrically by using the proper combination of control signals and by holding ALE/PROG low for 10 ms. The code array is written with all ―1‖s. The chip erase operation must be executed before the code memory can be re-programmed.Reading the Signature Bytes: The signature bytes are read by the same procedure as a normal verification of locations 030H, 031H, and 032H, except that P3.6 and P3.7 must be pulled to a logic low. The values returned are as follows.(030H) = 1EH indicates manufactured by Atmel(031H) = 51H indicates 89C51(032H) = FFH indicates 12V programming(032H) = 05H indicates 5V programmingProgramming InterfaceEvery code byte in the Flash array can be written and the entire array can be erased by using the appropriate combination of control signals. The write operation cycle is selftimed and once initiated, will automatically time itself to completion.All major programming vendors offer worldwide support for the Atmelmicrocontroller series. Please contact your local programming vendor for the appropriate software revision.Flash Programming and V erification Waveforms - High-voltage Mode (VPP = 12V)Flash Programming and V erification Waveforms - Low-voltage Mode (VPP = 5V)Flash Programming and Verification Characteristics TA = 0°C to 70°C, VCC = 5.0 ±10%Absolute Maximum Ratings**NOTICE: Str esses beyond those listed under ―Absolute Maximum Ratings‖ may cause permanent damage to the device. This is a stress rating only and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of this specification is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability.DC CharacteristicsTA = -40°C to 85°C, VCC = 5.0V ±20% (unless otherwise noted)Notes: 1. Under steady state (non-transient) conditions, IOL must be externally limited as follows:Maximum IOL per port pin: 10 mAMaximum IOL per 8-bit port: Port 0: 26 mAPorts 1, 2, 3: 15 mAMaximum total IOL for all output pins: 71 mAIf IOL exceeds the test condition, VOL may exceed the related specification. Pins arenot guaranteed to sink current greater than the listed test conditions.2. Minimum VCC for Power-down is 2V.AC CharacteristicsUnder operating conditions, load capacitance for Port 0, ALE/PROG, and PSEN = 100 pF; load capacitance for all other outputs = 80 pF.External Program and Data Memory CharacteristicsExternal Program Memory Read CycleExternal Data Memory Read CycleExternal Data Memory Write CycleExternal Clock Drive WaveformsExternal Clock DriveSerial Port Timing: Shift Register Mode Test Conditions (VCC = 5.0 V ±20%; Load Capacitance = 80 pF)Shift Register Mode Timing WaveformsAC Testing Input/Output Waveforms(1)Note: 1. AC Inputs during testing are driven at VCC - 0.5V for a logic 1 and 0.45V for a logic 0. Timing measurements are made at VIH min. for a logic 1 and VIL max. for a logic 0.Float Waveforms(1)Note: 1. For timing purposes, a port pin is no longer floating when a 100mV change from load voltage occurs. A port pin begins to float when 100mV change from the loaded VOH/VOL level occurs.AT89C51中文原文AT89C51是美国ATMEL公司生产的低电压，高性能CMOS8位单片机，片内含4k bytes的可反复擦写的只读程序存储器（PEROM）和128 bytes的随机存取数据存储器（RAM），器件采用A TMEL公司的高密度、非易失性存储技术生产，兼容标准MCS-51指令系统，片内置通用8位中央处理器（CPU）和Flash存储单元，功能强大AT89C51单片机可为您提供许多高性价比的应用场合，可灵活应用于各种控制领域。
交通毕设外文翻译
City Viaduct entrance ramp traffic character studyautor：LI Yingshua，XU HuiThe rapid development of the automobile industry and the relative lag of the road construction have constituted a prominent contradiction all over the world,particularly, in most of large cities. To cope with it,elevated roads have been built in many cities both at home and abroad. However, traffic jams frequentlyappear on elevated roads immediately after the completion of their construction. The awkward situation mainly results from the planning bug or the unsuitable control, apart from drastic increase in transportation demand. Elevated roads, ramps and ground roads areclosely interconnected in three-dimensional urban traffic networks.The mathematical modeling and numerical simulation were conducted for the sections of. elevated roads and for the interaction of elevated roadsand intersections on the ground. After having analyzed the complicated dynamic behavior on the elevated roads, some suggestions were put forward for the transportation planning and management. The contents of the dissertation are as follows:(1)By combining manpower survey with the video recording, a series of field measurementswere conducted on several sections of the elevated road system in Shanghai City and then the main characteristics of composed of the Common Language Runtime (CLR) and a unified set of class libraries. ations were established, which are suitable for the free flow and the congested flow respectively. And thus two important parameters, namely, the free flow speed and the jamming density, were determined. The fundamental diagram obtained from the measured data reveals three distinct traffic phases.(2) With the Wuning Of-fRamp of the Inner Ring Elevated road in Shanghai City as arepresentative case, meticulous observations were carried out on traffic flow at the intersection near the of-framp. And it was found that the squeezing effect of right-turning vehicles from the intersecting main road on the straight motion of vehicles from the of-framp is the main reason of the existing traffic jam. A modified 1- D model. With the modified model, numerical simulation was performed with special attention to the disturbing effect of right-turning vehicles. The results agree quite well with the observed data. The analysis shows that the squeezing effect, which exacerbates with the increasing number of right-turning vehicles, is the principal cause of congested traffic at certain intersec tions. The inappropriate design and construction of ramps in front of busy crossings enhances the congestion. Thus, installing the right-turning traffic lights may bea promising way of solving the problem.(3) There exist severe problems in the transportation on elevated road system in ShanghaiCity, such as frequent congestions or jams on the elevated roads and their ramps. For this reason, measures of controlling the on-ramp traffic with timing signals were suggested in this dissertation. The reasonable timing scheme was recommended for signal controlling. On the basis of an anisotropic hydrodynamic traffic model developed by our research group, a ramp-effect term was introduced in the motion equation and traffic flows on the elevated road sections near the on-ramp were numerically simulated.The results show that signaling control of on-ramp is helpful for the improvement of traffic on the elevated roads. We also found the best timing scheme after comparison among six choices of signaling period.(4) The gear-alternating regulation was first actualized at the interfluent location ofon-ramps in Shanghai elevated roads, which was theoretically studied in this dissertation.Different traffic flow models were established for the cases with and without the alternate running rule based on the FI cellular automaton traffic model. With the models, the traffic behavior at the interfluent location of on-ramp was investigated and some results were concluded. When there are many inflowing vehicles on the elevated road and ramp, the traffic situation on the elevated road with the alternating regulation is much better than that without the regulation; when there are less inflowing vehicles, the elevated road situation keeps unvaried on the whole in the two cases. The vehicles on the elevated road and the on-ramp are easily to move forward with 1: 1 pro-portion in congestion or free flow states and often with 2: 1 proportion in the medium-speed flow.(5) The weaving areas often turned into the bottleneck on the elevated roads. On the basisof the NS cellular automaton traffic model, the weaving section with one-lane main road was simulated and analyzed.For the free traffic flow, weaving operations almost has no influence on the system, even with the weaving length being increased. On the other hand, when the traffic flow is in congested state, weaving conflicts have negative effects on the system. The traffic situation will be improved with the increase of weaving length. Our simulation results suggest that the length of weaving sections need not to be inappropriately increased, and a proper medium value can be chosen to get an optimal traffic situation.Finally, the prospect was briefly reviewed for the future advances in the research of urban traffic flows in China.City expressway on-ramp control are mainly local single ramp Independent control and a handful of ramp coordination control, the current game.The Department of ramp control mostresearch only for independent ramp control research.Investigate. Many city expressway ramp was very close, a lot of ramp.The distance is only 200~ 300 m, the ramp in the operation of traffic.Flow interference is very serious, in this case on the relative.The entrance ramp for independent control is not reasonable. In this paper Shanghai City Expressway actual testing data, the 2 main near.Distance ( distance of less than 450 m ) entrance ramp traffic flow characteristics in study.Based on bus enter or exit operation mechanism，the realistic traffic capacity model of bus stop is established combined with reduced loading areas of bus stop，and then，the standard design mode of bus bay stop is worked out．And according to the different road grade of main trunk road，sub －trunk road and branch road，model and sizes of bus bay stop set at the intersections and road sections are made integrated designs．The design mode has been applied in the Suzhou Industrial Park，which can provide essential reference for urban road design，especially the bus stop．Traffic control means is: focus on the elevated road itself from macroscopical angle measures, for articulation section microscopic insufficient consideration. Because the present our country real time traffic information collection.Technology needs to be further improved, by means of avoiding Ramp Traffic Control Regional congestion queuing and the validity of the restricted. In view of the exit ramp.Link Road and traffic flow characteristics, traffic management has taken a different turn through means of organization, including lane function division, ban and other methods, to hold block queuing and the improvement effect was more timely. But in view of different exit ramp connecting sections, how to adopt the different traffic organization,At present there is no systematic theoretical analysis and research. How to make a continuous flow with stop to organic join, make full use of resources, make the system of the optimal, for elevated road and ground road system construction and operation a special significance.Ramp presence becomes limiting articulation section inlet tract operation important factor, according to the traffic demand and supply balance principle, should ensure that the exit ramp connecting the highway capacity and the ramp and the ground to flow to match, make traffic can timely discharge, system is maintained in a relatively stable state. To ban the articulation section, traffic operation mode and the general intersection similarity, this does not do the special analysisTraffic control measures that is by setting the signal lamp, the conflict points distribution of traffic flow in different time periods, so as to achieve at the same elevation pavement to eliminate conflict point; stereo cross measure that is by setting the engineering facilities, the conflicting traffic arrangement in different elevation on the road, in order to achieve various time range to eliminate the conflict point; roundabout measures that is by setting the large center island, interwoven into the ring road and vehicle running around the island, will intersect the traffic stream is converted to interlaced stream, at various time within the same elevation on the road to eliminate the conflict points, far leading circuitous measures its practice is actually the conflict is converted to interlaced, disappear in addition to conflict point.City Road in intersection traffic flow, has been generally take the measures to eliminate, reduce conflict point. According to interweave, confluent, diverting traffic impact on the relatively few studies and countermeasures. If the city road traffic volume is not within the time period or region, interweave, shunt, the effect of relatively in acceptable condition, study its impact on traffic and Countermeasure of urgency is not obvious, but as the city increase of traffic, especially the city expressway construction, it is necessary to interweave shunt, confluence, the implications for further study, and research to improve the flow of traffic improvement measures. Based on the characteristics of city road network, its characteristic is generally more developed road network, the relatively small spacing, a lot of old urban road network distance between 200 to about 600 m, mixed traffic flow on road network traffic capacity influence is increasingly serious, with the city expressway construction, elevated expressway in the city built the use of existing road width layout, avoid a large number of residents, this mode of construction in large city, typical example is the Shanghai inner ring viaduct. With the elevated expressway construction, to contact the rapid transit and ground slow traffic, according to the traffic needs to set up the ramp traffic conversion, but according to now run the examples, more traffic problems in the ramp and ground traffic conversion between. In view of the above problems, the article on the city road network space is smaller under the conditions of mixed flow of traffic capacity and the effect of improving measure to undertake preliminary discuss on network distance, the larger is the special study.With the development of City Road, city road builders gradually realize that: in the city road network conditions, especially because of various historical reasons, the planning of road network conditions and causes of expressway construction demand there is a gap between. But the city expressway construction is the city development, transportation development one of the important means to solve, it is necessary to research the road builders in variousadverse conditions, improving the traffic capacity of the road, in the limited hardware construction conditions to provide greater traffic capacity. On the light control, grade separation construction, various research and engineering example, the crossover controlled and improved not only devoted to exploring, concern the improvement of city expressway ramp with surface intersections between matching problem, undertake preliminary discuss, the generalized point, this article referred to the improvement measures not only can be applied to the expressway and the ground city crossing engineering, various influences larger sections, intersections can refer to.。
道路交通工程专业外文翻译外文文献英文文献
土木工程学院交通工程专业中英文翻译Road Design专业：交通工程英文原文The Basics of a Good RoadWe have known how to build good roads for a long time. Archaeologists have found ancient Egyptian roadsthat carried blocks to the pyramids in 4600 BCE. Later,the Romans built an extensive road system, using the same principles we use today. Some of these roads arestill in service.If you follow the basic concepts of road building, you will create a road that will last. The ten commandments of a good road are:（1）Get water away from the road（2）Build on a firm foundation（3）Use the best materials（4）Compact all layers properly（5）Design for traffic loads and volumes（6）Design for maintenance（7）Pave only when ready（8）Build from the bottom up（9）Protect your investment（10）Keep good records1．Get water away from the roadWe can’t overemphasize the importance of good drainage.Engineers estimate that at least 90% of a road’s problems can be related to excess water or to poor waterdrainage. Too much water in any laye r of a road’sstructure can weaken that layer, leading to failure.In the surface layer, water can cause cracks and potholes. In lower layers it undermines support, causing cracks and potholes. A common sign of water in an asphalt road surface is alligator cracking — an interconnected pattern of cracks forming small irregular shaped pieces that look like alligator skin. Edge cracking, frost heaves, and spring breakup of pavements also point to moisture problems.To prevent these problems remember that water:• flows downhill• needs to flow someplace• is a problem if it is not flowingEffective drainage systems divert, drain and dispose of water. To do this they use interceptor ditches and slopes,road crowns, and ditch and culvert systems.Divert —Interceptor ditches, located between the road and higher ground along the road, keep the water from reaching the roadway. These ditches must slope so they carry water away from the road.Drain —Creating a crown in the road so it is higher along the centerline than at the edges encourages water to flow off the road. Typically a paved crown should be 1⁄4" higher than the shoulder for each foot of width from the centerline to the edge. For gravel surfaces the crownshould be 1⁄2" higher per foot of width. For this flow path to work, the road surface must be relatively water tight. Road shoulders also must be sloped away from the road to continue carrying the flow away. Superelevations (banking) at the outside of curves will also help drainthe road surface.Dispose —A ditch and culvert system carries water away from the road structure. Ditches should be at least one foot lower than the bottom of the gravel road layer that drains the roadway. They must be kept clean and must be sloped to move water into natural drainage. If water stays in the ditches it can seep back into the road structure and undermine its strength. Ditches should also be protected from erosion by planting grass, or installing rock and other erosion control measures. Erosion can damage shoulders and ditches, clog culverts, undermine roadbeds, and contaminate nearby streams and lakes. Evaluate your ditch and culvert system twice a year to ensure that it works. In the fall, clean out leaves and branches that can block flow. In spring, check for and remove silts from plowing and any dead plant material left from the fall.2．Build on a firm foundationA road is only as good as its foundation. A highway wears out from the top down but falls apart from the bottom. The road base must carry the entire structure and the traffic that uses it.To make a firm foundation you may need to stabilize the roadbed with chemical stabilizers, large stone called breaker run, or geotextile fabric. When you run into conditions where you suspect that the native soil is unstable, work with an engineer to investigate the situation and design an appropriate solution.3．Use the best materialsWith all road materials you “pay now or pay later.” Inferior materials may require extensive maintenance throughout the road’s life. They may also force you to replace the road prematurely.Crushed aggregate is the best material for the base course. The sharp angles of thecrushed material interlock when they are compacted. This supports the pavement and traffic by transmitting the load from particle to particle. By contrast, rounded particles act like ballbearings, moving under loads.Angular particles are more stable than rounded particles.Asphalt and concrete pavement materials must be of the highest quality, designed forthe conditions, obtained from established firms, and tested to ensure it meets specifications.4．Compact all layersIn general, the more densely a material is compacted, the stronger it is. Compaction also shrinks or eliminates open spaces (voids) between particles. This means that less water can enter the structure. Water in soil can weaken the structure or lead to frost heaves. This is especially important for unsurfaced (gravel) roads. Use gravel which has a mix of sizes (well-graded aggregate) so smaller particles can fill the voids between larger ones. Goodcompaction of asphalt pavement lengthens its life.5．Design for traffic loads and volumesDesign for the highest anticipated load the road will carry. A road that has been designed only for cars will not stand up to trucks. One truck with 9 tons on a single rear axle does as much damage to a road as nearly 10,000 cars.Rural roads may carry log trucks, milk trucks, fire department pumper trucks, or construction equipment. If you don’t know what specific loads the road w ill carry, a good rule of thumb is to design for the largest piece of highway maintenance equipment that will be used on the road.A well-constructed and maintained asphalt road should last 20 years without major repairs or reconstruction. In designing a road, use traffic counts that project numbers and sizes of vehicles 20 years into the future. These are only projections, at best, but they will allow you to plan for traffic loadings through a road’s life.6．Design for maintenanceWithout maintenance a road will rapidly deteriorate and fail. Design your roads so they can be easily maintained. This means:• adequate ditches that can be cleaned regularly• culverts that are marked for easy locating in the spring• enough space for snow after it is plowed off the road• proper cross slopes for safety, maintenance and to avoid snow drifts• roadsi des that are planted or treated to prevent erosion• roadsides that can be mowed safelyA rule of thumb for adequate road width is to make it wide enough for a snowplow to pass another vehicle without leaving the travelled way.Mark culverts with a post so they can be located easily.7．Pave only when readyIt is not necessary to pave all your roads immediately. There is nothing wrong with a well-built and wellmaintained gravel road if traffic loads and volume do not require a paved surface. Three hundred vehicles per day is the recommended minimum to justify paving.Don’t assume that laying down asphalt will fix a gravel road that is failing. Before youpave, make sure you have an adequate crushed stone base that drains well and is properly compacted. The recommended minimum depth of crushed stone base is 10" depending on subgrade soils. A road paved only when it is ready will far outperform one that is constructed too quickly.8．Ê Build from the bottom upThis commandment may seem obvious, but it means that you shouldn’t top dress or resurface a road if the problem is in an underlying layer. Before you do any road improvement, locate the cause of any surface problems. Choose an improvement technique that will address the problem. This may mean recycling or removing all road materials down to the native soil and rebuilding everything. Doing any work that doesn’t solve the problem is a waste of money and effort.9．Ê Protec t your investmentThe road system can be your municipality’s biggest investment. Just as a home needs painting or a new roof, a road must be maintained. Wisconsin’s severe climate requires more road maintenance than in milder places. Do these important maintenance activities: Surface —grade, shape, patch, seal cracks, control dust, remove snow and iceDrainage —clean and repair ditches and culverts; remove all excess materialRoadside —cut brush, trim trees and roadside plantings, control erosionTraffic service —clean and repair or replace signsDesign roads with adequate ditches so they can be maintained with a motor grader. Clean and grade ditches to maintain proper pitch and peak efficiency. After grading, remove all excess material from the shoulder.10．Keep good recordsYour maintenance will be more efficient with good records. Knowing the road’s construction, life, and repair history makes it much easier to plan and budget its future repairs. Records can also help you evaluate the effectiveness of the repair methods and materials you used.Good record keeping starts with an inventory of the system. It should include the history and surface condition of the roadway, identify and evaluate culverts and bridges, note ditch conditions, shoulders, signs, and such structures as retaining walls and guardrails.Update your inventory each year or when you repair or change a road section. A formal pavement management system can help use these records and plan and budget road improvements.ResourcesThe Basics of a Good Road#17649, UW-Madison, 15 min. videotape. Presentsthe Ten Commandments of a Good Road. Videotapes are loaned free through County Extension offices.Asphalt PASER Manual(39 pp), Concrete PASER Manual (48 pp), Gravel PASERManual (32 pp). These booklets contain extensive photos and descriptions of road surfaces to help you understand types of distress conditions and their causes. A simple procedure for rating the condition helps you manage your pavements and plan repairs.Roadware, a computer program which stores and reports pavement conditioninformation. Developed by the Transportation Information Center and enhanced by the Wisconsin Department of Transportation, it uses the PASER rating system to providefive-year cost budgets and roadway repair/reconstruction priority lists.Wisconsin Transportation Bulletin factsheets, available from the Transportation Information Center (T.I.C.).Road Drainage, No. 4. Describes drainage for roadways, shoulders, ditches, and culverts.Gravel Roads, No. 5. Discusses the characteristics of a gravel road and how to maintain one.Using Salt and Sand for Winter Road Maintenance,No. 6. Basic information and practical tips on how to use de-icing chemicals and sand.Culverts—Proper Use and Installation, No. 15. Selecting and sizing culverts, designing, installing and maintaining them.Geotextiles in Road Construction/Maintenance andErosion Control, No. 16. Definitions and common applications of geotextiles onroadways and for erosion control.T.I.C. workshops are offered at locations around the state.Crossroads,an 8-page quarterly newsletter published by the T.I.C. carries helpfularticles, workshop information, and resource lists. For more information on any of these materials, contact the T.I.C. at 800/442-4615.中文译文一个良好的公路的基础长久以来我们已经掌握了如何铺设好一条道路的方法，考古学家发现在4600年古埃及使用建造金字塔的石块铺设道路，后来，罗马人使用同样的方法建立了一个庞大的道路系统，这种方法一直沿用到今天。
毕业设计论文外文文献翻译智能交通信号灯控制中英文对照
英语原文Intelligent Traffic Light Controlby Marco Wiering The topic I picked for our community project was traffic lights. In a community, people need stop signs and traffic lights to slow down drivers from going too fast. If there were no traffic lights or stop signs, people’s lives would be in danger from drivers going too fast.The urban traffic trends towards the saturation, the rate of increase of the road of big city far lags behind rate of increase of the car.The urban passenger traffic has already become the main part of city traffic day by day and it has used about 80% of the area of road of center district. With the increase of population and industry activity, people's traffic is more and more frequent, which is unavoidable. What means of transportation people adopt produces pressure completely different to city traffic. According to calculating, if it is 1 to adopt the area of road that the public transport needs, bike needs 5-7, car needs 15-25, even to walk is 3 times more than to take public transits. So only by building road can't solve the city traffic problem finally yet. Every large city of the world increases the traffic policy to the first place of the question.For example，according to calculating, when the automobile owning amount of Shanghai reaches 800,000 (outside cars count separately ), if it distributes still as now for example: center district accounts for great proportion, even when several loop-lines and arterial highways have been built up , the traffic cannot be improved more than before and the situation might be even worse. So the traffic policy Shanghai must adopt , or called traffic strategy is that have priority to develop public passenger traffic of city, narrow the scope of using of the bicycle progressively , control the scale of growth of the car traffic in the center district, limit the development of the motorcycle strictly.There are more municipals project under construction in big city. the influence on the traffic is greater.Municipal infrastructure construction is originally a good thing of alleviating the traffic, but in the course of constructing, it unavoidably influence the local traffic. Some road sections are blocked, some change into an one-way lane, thus the vehicle can only take a devious route . The construction makes the road very narrow, forming the bottleneck, which seriously influence the car flow.When having stop signs and traffic lights, people have a tendency to drive slower andlook out for people walking in the middle of streets. To put a traffic light or a stop sign in a community, it takes a lot of work and planning from the community and the city to put one in. It is not cheap to do it either. The community first needs to take a petition around to everyone in the community and have them sign so they can take it to the board when the next city council meeting is. A couple residents will present it to the board, and they will decide weather or not to put it in or not. If not put in a lot of residents might be mad and bad things could happened to that part of the city.When the planning of putting traffic lights and stop signs, you should look at the subdivision plan and figure out where all the buildings and schools are for the protection of students walking and riding home from school. In our plan that we have made, we will need traffic lights next to the school, so people will look out for the students going home. We will need a stop sign next to the park incase kids run out in the street. This will help the protection of the kids having fun. Will need a traffic light separating the mall and the store. This will be the busiest part of the town with people going to the mall and the store. And finally there will need to be a stop sign at the end of the streets so people don’t drive too fast and get in a big accident. If this is down everyone will be safe driving, walking, or riding their bikes.In putting in a traffic light, it takes a lot of planning and money to complete it. A traffic light cost around $40,000 to $125,000 and sometimes more depending on the location. If a business goes in and a traffic light needs to go in, the business or businesses will have to pay some money to pay for it to make sure everyone is safe going from and to that business. Also if there is too many accidents in one particular place in a city, a traffic light will go in to safe people from getting a severe accident and ending their life and maybe someone else’s.The reason I picked this part of our community development report was that traffic is a very important part of a city. If not for traffic lights and stop signs, people’s lives would be in danger every time they walked out their doors. People will be driving extremely fast and people will be hit just trying to have fun with their friends. So having traffic lights and stop signs this will prevent all this from happening.Traffic in a city is very much affected by traffic light controllers. When waiting for a traffic light, the driver looses time and the car uses fuel. Hence, reducing waiting times before traffic lights can save our European society billions of Euros annually. To make traffic light controllers more intelligent, we exploit the emergence of novel technologies such as communication networks and sensor networks, as well as the use of more sophisticated algorithms for setting traffic lights. Intelligent traffic light control does not only mean thattraffic lights are set in order to minimize waiting times of road users, but also that road users receive information about how to drive through a city in order to minimize their waiting times. This means that we are coping with a complex multi-agent system, where communication and coordination play essential roles. Our research has led to a novel system in which traffic light controllers and the behaviour of car drivers are optimized using machine-learning methods.Our idea of setting a traffic light is as follows. Suppose there are a number of cars with their destination address standing before a crossing. All cars communicate to the traffic light their specific place in the queue and their destination address. Now the traffic light has to decide which option (ie, which lanes are to be put on green) is optimal to minimize the long-term average waiting time until all cars have arrived at their destination address. The learning traffic light controllers solve this problem by estimating how long it would take for a car to arrive at its destination address (for which the car may need to pass many different traffic lights) when currently the light would be put on green, and how long it would take if the light would be put on red. The difference between the waiting time for red and the waiting time for green is the gain for the car. Now the traffic light controllers set the lights in such a way to maximize the average gain of all cars standing before the crossing. To estimate the waiting times, we use 'reinforcement learning' which keeps track of the waiting times of individual cars and uses a smart way to compute the long term average waiting times using dynamic programming algorithms. One nice feature is that the system is very fair; it never lets one car wait for a very long time, since then its gain of setting its own light to green becomes very large, and the optimal decision of the traffic light will set his light to green. Furthermore, since we estimate waiting times before traffic lights until the destination of the road user has been reached, the road user can use this information to choose to which next traffic light to go, thereby improving its driving behaviour through a city. Note that we solve the traffic light control problem by using a distributed multi-agent system, where cooperation and coordination are done by communication, learning, and voting mechanisms. To allow for green waves during extremely busy situations, we combine our algorithm with a special bucket algorithm which propagates gains from one traffic light to the next one, inducing stronger voting on the next traffic controller option.We have implemented the 'Green Light District', a traffic simulator in Java in which infrastructures can be edited easily by using the mouse, and different levels of road usage can be simulated. A large number of fixed and learning traffic light controllers have already been tested in the simulator and the resulting average waiting times of cars have been plotted and compared. The results indicate that the learning controllers can reduce average waiting timeswith at least 10% in semi-busy traffic situations, and even much more when high congestion of the traffic occurs.We are currently studying the behaviour of the learning traffic light controllers on many different infrastructures in our simulator. We are also planning to cooperate with other institutes and companies in the Netherlands to apply our system to real world traffic situations. For this, modern technologies such as communicating networks can be brought to use on a very large scale, making the necessary communication between road users and traffic lights possible.中文翻译：智能交通信号灯控制马克·威宁我所选择的社区项目主题是交通灯。
毕设必备道路桥梁专业毕业设计英文翻译(英文原文+中文翻译)
Accident Analysis and PreventionThis paper describes a project undertaken to establish a self-explaining roads (SER) design programmeon existing streets in an urban area. The methodology focussed on developing a process to identifyfunctional road categories and designs based on endemic road characteristics taken from functionalexemplars in the study area. The study area was divided into two sections, one to receive SER treatments designed to maximise visual differences between road categories, and a matched control area to remainuntreated for purposes of comparison. The SER design for local roads included increased landscaping andcommunity islands to limit forward visibility, and removal of road markings to create a visually distinctroad environment. In comparison, roads categorised as collectors received increased delineation, additionof cycle lanes, and improved amenity for pedestrians. Speed data collected 3 months after implementationshowed a significant reduction in vehicle speeds on local roads and increased homogeneity of speeds onboth local and collector roads. The objective speed data, combined with r esidents’ speed choice ratings,indicated that the project was successful in creating two discriminably different road categories.2010 Elsevier Ltd. All rights reserved.1. Introduction1.1. BackgroundChanging the visual characteristics of roads to influencedriver behaviour has come to be called the self-explaining roads(SER) approach (Theeuwes, 1998; Theeuwes and Godthelp, 1995;Rothengatter, 1999). Sometimes referred to as sustainable safety,as applied in the Netherlands, the logic behind the approach isthe use of road designs that evoke correct expectations and drivingbehaviours from road users (Wegman et al., 2005; Weller etal., 2008). The SER approach focuses on the three key principlesof functionality, homogeneity, and predictability (van Vliet andSchermers, 2000). In practice, functionality requires the creation ofa few well-defined road categories (e.g., through roads, distributorroads, and access roads) and ensuring that the use of a particularroad matches its intended function. Multifunctional roadslead to contradictory design requirements, confusion in the mindsof drivers, and incorrect expectations and inappropriate drivingbehaviour. Clearly defined road categories promote homogeneity intheir use and prevent large differences in vehicle speed, direction,and mass. Finally, predictability, or recognisability, means keepingthe road design and layout within each category as uniform as possibleand clearly differentiated from other categories so that thefunction of a road is easily recognised and will elicit the correctbehaviour from road users. The SER approach has been pursued tothe largest extent in the Netherlands and the United Kingdom but ithas also been of some interest inNewZealand. In 2004, the NationalRoad Safety Committee and the Ministry of Transport articulateda new National Speed Management Initiative which stated “Theemphas is is not just on speed limit enforcement, it includes perceptualmeasures that influence the speed that a driver feels is appropriatefor the section of road upon which they are driving–in effect the ‘selfexplainingroad”’ (New Zealand Ministry of Transport, 2004).In cognitive psychological terms, the SER approach attempts toimprove road safety via two complementary avenues. The first is toidentify and use road designs that afford desirable driver behaviour.Perceptual properties such as road markings, delineated lane width,and roadside objects can function as affordances that serve as builtininstructions and guide driver behaviour, either implicitly orexplicitly (Charlton, 2007a; Elliott et al., 2003; Weller et al., 2008).This work is more or less a direct development of work on perceptualcountermeasures, perceptual cues in the roading environmentthat imply or suggest a particular speed or lane position, eitherattentionally or perceptually (Charlton, 2004, 2007b; Godley et al.,1999).A second aspect of the SER approach is to establish mentalschemata and scripts, memory representations that will allowroad users to easily categorise the type of road on which they are.1.2. Localised speed managementThe traditional approaches to improving speed management,traffic calming and local area traffic management (LATM) havefocussed on treating specific problem locations or “black spots”in response to crash occurrences or complaints from the public(Ewing, 1999). A potential disadvantage of these approaches is thataddressing the problem with localised treatments can lead to are-emergence of the problem at another location nearby. Further,when applied inappropriately, localised approaches may addressthe problem from only one perspective, without considering theimpact on other types of road users or residents. When traffic calmingtreatments rely on physical obstacles such as speed humpsthey can be very unpopular with bothresidents and road users andcan create new problems associated with noise, maintenance, andvandalism (Martens et al., 1997).From an SER perspective, treatments that are highly localizedor idiosyncratic may do more harm than good by adding to themultiplicity of road categories and driver uncertainty, rather thanbuilding driver expectations around a few uniform road types.Instead of considering a single location in isolation, SER roaddesigns are considered within a hierarchy of road functions; e.g.,access roads, collector roads, and arterial roads. Although SERschemes may employ physical design elements used in trafficcalming schemes (e.g., road narrowing with chicanes and accesscontrols) they also employ a range of more visually oriented featuressuch as median and edge line treatments, road markings,pavement surfaces, and roadside furniture. For an effective SERscheme it is important to select the combination of features that will afford the desired driver speeds and to ensure their consistentuse to form distinct categories of road types (van der Horst andKaptein, 1998; Wegman et al., 2005).road category that would meet the three SER principles of functional use, homogeneous use, and predictable use. Herrstedt (2006)reported on the use of a standardised catalogue of treatments compiledfrom researcher and practitioner advice. Goldenbeld and vanSchagen (2007) used a survey technique to determine road characteristicsthat minimise the difference between drivers’ ratingsof preferred speed and perceived safe speed and select road featuresthat make posted speeds “credible”. Aarts and Davidse (2007)used a driving simulator to verify whether the “essential recognisabilitycharacteristics” of different road classes conformed to theexpectations of road users. Weller et al. (2008) employed a range of statistical techniques, including factor analysis and categoricalclustering to establish the road characteristics that drivers use tocategorise different road types.The practical difficulties of implementing an SER system thusbecome a matter of finding answers to a series of questions. Howdoes one create a discriminable road hierarchy for an existingroad network? What road characteristics should be manipulatedto establish category-defining road features? How can SER roadfeatures and selection methods be made relevant and appropriatefor a local context? (Roaddesigns appropriate for The Netherlandswould not be suitable in New Zealand, in spite of its name.) A surveyof national and international expert opinion in order establishcategory-defining road features for New Zealand roads revealedthat the regional character and local topography of roads oftenundercut the usefulness of any standardised catalogue of designcharacteristics (Charlton and Baas, 2006).1.4. Goals of the present projectThe project described in this paper sought to develop anddemonstrate an SER process based on retrofitting existing roadsto establish a clear multi-level road hierarchy with appropriatedesign speeds, ensuring that each level in the hierarchy possesseda different “look and feel”. Rather than transferring SER designs already in use internationally, the project attempted to develop amethod that would build on the features of roads in the local area;extending road characteristics with desirable affordances to otherroads lacking them and creating discriminable road categories inthe process. Of interest was whether such a process could producecost-effective designs and whether those designs would be effectivein creating different road user expectations and distinct speedprofiles for roads of different categories.2. MethodsThe research methodology/SER design process developed forthis project progressed through a series of five stages: (1) selectionof study area; (2) identification of the road hierarchy; (3) analysisof the road features; (4) development of a design template; and (5)implementation and evaluation of the SER treatments. Each of thestages is described in the sections that follow.2.1. Selection of study areaThe study area for this project (Pt England/Glen Innes in Auckland)was selected in consultation with a project steering groupcomprised of representatives from the Ministry of Transport, NewZealand Transport Agency, New Zealand Police, and other localtransport and urban agencies. The study area was an establishedneighbourhood contained amix of private residences, small shops,schools, and churches, and was selected, in part, because of its historyof cyclist, pedestrian and loss of controlcrashes, almost twicethe number。
道路毕设翻译
本科生毕业设计（论文）外文科技文献译文译文题目乡村双车道高速公路期望的安全变现的预测(外文题目) Prediction of the Expected Safety Performanceof Rural Two-Lane Highways学院(系) 土木工程学院专业土木工程道路方向学号学生姓名日期指导教师签名日期┊┊┊┊┊┊┊┊┊┊┊┊┊装┊┊┊┊┊订┊┊┊┊┊线┊┊┊┊┊┊┊┊┊┊┊┊┊乡村双车道高速公路期望的安全表现的预测1.介绍在高速公路安全管理上一个最重要的空白是缺乏估计一条现有或计划的车行道的安全表现一个可靠方法。
事故记录系统由高速公路代办处开发并且维护监测他们的车行道安全表现，但这些性能提供历史或追溯数据。
有效管理需要一个前瞻性的观点。
公路工程师需要知道没有什么巷道的安全性能是在最近或遥远的过去，但是如果特别采取建议行动起来的话它会在现在活着将来表现出来。
在过去，巷道的当前或未来的安全性能评估什么时候需要，他们已经开发四种途径：从历史的偶然平均为数据，从统计预测模型进行回归分析，结果前后研究，由经验丰富的工程师和专家判断。
每一种方法单独使用有下述重大的弱点。
结合每一种事故预测法，一种新的方法应运而生。
这种新的事故预测方法应用到农村双车道公路中，是本报告的主题。
从历史事故数据的估计历史事故数据是一个巷道的安全性能的重要指标，但是他们遭受的弱点是高度可变。
鉴于这种高变异性，使用一到三年的事故数据这样相对短期的样本来估计长期期望的事故率是很困难的。
特别是对于农村道路路段和交叉口位置，事故时非常罕见的，或者有许多地方在近几年来最多发生过一次事故。
如果一个地方在过去的几年中没有发生过事故而就认为它将永远不会发生事故是不正确的，但是这些可靠的数据对与这些地方仅仅提供了一个不足的依据来评估它长期预期的安全性能。
基于安全的行车道改进程序常常被用作事故记录来辨认高事故地点的检测系统控制。
一个高事故地点是车行道路段或交叉口，因为它比在一段时间（通常为1到3年）指定的阀值大的多。
重庆交通大学毕业设计中英文翻译
Legal Environment for Warranty ContractingIntroductionIn the United State, state highway agencies are under increasing pressure to provide lasting and functional transporting infrastructures rapidly and at an optimum life-cycle cost. To meet the challenge, state highway agencies are expected to pursue innovative practices when programming and executing projects. One area of the innovative practices is the implementation of long-term, performance-based warranties to shift maintenance liabilities to the highway industry. Use of warranties by state highway agencies began in the early-1990s after the Federal Highway Administration 's (FHWA) decision to allow warranty provisions to be included in construction contracts for items over which the contractor had complete control (Bayraktar et al. 2004). Special Experiment Project Number 14(SEP-14) was created to study the effects of this and other new techniques. Over the past decade, some states have incorporated this innovative technique into their existing programs. Projects have ranged from New Mexico 's 20-year warranty for the reconstruction of US550 to smaller scale projects, such as bridge painting and preventative maintenance jobs.These projects have met with varying degrees of success, causing some states to broaden the use of warranties, whereas others have abandoned them completely. Several states have sacrificed time and money to fine tune the use of warranties. However, on a national level, there is still a need for research and the exchange of ideas and best practices. One area that needs further consideration is the legal environment surrounding the use of warranties. Preliminary use in some states has required changes to state laws and agency regulations, as well as the litigation of new issues. This paper will discuss the laws and regulations needed to successfully incorporate warranties into current contracting practices and avoid litigation. The state of Alabama is used as an example of a state considering the use of long-term, performance-based warranties and proposals for laws and regulations will be outlined. This paper persents a flowchart to help an agency determine if a favorable legal environment exists for the use of warranties.Warranty Contracting in Highway ConstructionA warranty in highway construction, like the warranty for a manufactured product, is a guarantee that holds the contractor accountable for the repair and replacement of deficiencies under his or her control for a given period of time. Warranty provisions were prohibited in federal-aid infrastrure projects until the passage of the Intermodal Surface Transportation Efficiency Act in 1991 because warranty provisions could indirectly result in federal aid participation in maintenance costs, which at that time were a federal aid nonparticipating item(FHWA 2004). Under the warranty interim final rule that was published on April 19, 1996, the FHWA allwoed warranty provisions to be applied only to items considered to be within the control of contractors. Ordinary wear and tear, damage caused by others, and routine maintenance remained the responsibility of the state highway agencies(Anderson and Russel 2001). Eleven states participated in the warranty experiment under Special Experiment Project Number 14 referred to as SEP-14, which was created by the FHWA to study the effects of innovative contracting techniques. Warranty contracting was one of the four innovative techniques that FHWA investigated under SEP-14 and the follo-on SEP-15 program.In accordance with the National Cooperative Highway Research Program Synthesis 195(Hancher 1994), a warranty is defined as a guarantee of the integrity of a product and the maker's responsibility for the repair or replacement of the deficiencies. A warranty is used to specify the desired performance characeristics of a particular product over a specified period of time and to define who is responsible for the product (Blischke1995). Warranties are typically assigned to the prime contractor, but may bepassed down to the paving contractors as pass-through warranties.The warranty approach in highway construction contrasts sharply with traditional highway contracting practices. Under the standard contracting option, the state highway agencies provide a detailed design and decide on the construction processes and materials to be used. Contractors perform the construction and bear no responsibility for future repairs once the project is accepted. Stringent quality control and inspection are necessary to make sure that contractors are complying with the specifications and the design. The warranty approach, usually used with performance-based specifications, changes almost every step in the standard contracting system. The changes go beyond the manner in which projects are bid, awarded, and constructed. Most important, contractors are bound by the warranty and are required to come back to repair and maintain the highway whenever certain threshold values are exceeded. In return for the shift in responsibility, contractors are given the freedom to select construction materials, methods, and even mix designs.Legal assessment framework for warranty contractingAs public sector organizations, state highway agencies must follow state laws and proper project procurement procedures. State legislation impacting state highway agencies include statutes on public work, highways and roads, state government, and special statutes. These statutes define general responsibilities and liabilities of the state highway agency and must be investigated before a state highway agency moves to any innovative contracting method. Additionally, the state highway agency may develop appropriate regulatory standards and procedures tailored to meet special needs. State highway agencies should also investigate and assess warranties contract and construction.In order to develop a legal and contractual framework against which to evaluate the state of Alabama and other states not active in warranty contracting the writers reviewed the statutes in numerous states that are active in warranty contracting. Ohio, Michigan, Minnesota, Florida, Texas, Illinois, Montana, and others have all been more or less active in warranty contracting. Their statutes were reviewed, as well as the specifications they use for measuring actual road performance against warranted performance. Also, numerous national studies were reviewed. The writers determined that regardless of whether warranties are imposed by legislative mandate or initiated by a state DOT or other body, there are three elements that are consistently found in successful programs, and these elements often require modification of the existing statues. These three elements are design-build contracting, bidding laws that allow for flexibility and innovation, and realistic bonding requirements. Given those elements as a starting point, the actual contract specifications must address when the warranty period commences, the inspection frequency, clear defect definitions, allocation of responsibility for repair, emergency maintenance, circumstances that void the warranty, and dispute resolution.The foregoing statutes and regulations are termed the legal assessment framework for performance warranties. The three broad steps in the framework: initiation of warranty contracting, statute assessment, and regulatory assessment are discussed in detail in the following sections.Initiation of WarrantiesSeveral states initiated the use of warranties as a result of a legislative mandate. For example, in 1999, the Illinois legislature passed a bill that required 20 of the projects outlined in the Illinois Department of Transportation 's Five Year Plan to include 5-year performance warranties (IDOT 2004). Ten of those projects were to be designed to have 35 life cycles (Illinois Compiled StatutesCh.605*5/4-410). Also in 1999,Ohio began using warranties due to a legislative mandate that required a minimum of one-fifth of road construction projects to be bid with a warranty. According to Ohio Revised Code *5525.25, the requirements were later changed on the suggestion of the highway agency to makethe minimums into maximums so it could spend more time evaluating what types or projects are best suited for warranties(ODOT 1999). The warranties were to range from 2 to 7 years, depending on the type of construction. Finally, in a less demanding mandate, the Michigan Compiled Laws*247.661, in a state highway funds appropriation bill, included the instruction that, ”the Department [of Transportation] shall, where possible, secure warranties of not less than five-year, full replacement guarantee for contracted construction work.. ”These types of mandates generally require the agency to first come up with an outline of how it plans to incorporate these directives into existing procedures and specifications, as well as prepare reports regarding the success of these programs and their cost effectiveness.Alternatively, some agencies begin the use of warranties on their own initiative. In Texas, the State Comptroller 's Office issued a report on the Department of Transportation 's (DOT) operations and strongly recommended the use of more innovative methods, including warranties, to better meet the transportation needs of the state(Strayhorn2001). As a result, the Texas Transportation Institute commenced its own investigation of warranties and developed an implementation plan for the Texas DOT(Anderson et al.2006). One of the reasons cited for the study was the potential for a future legislative mandate, and the need to research the area before the agency wad forced to make use of warranties. Montana acted without any government influence by initiating a bill(Bill Draft No.LC0443) that called for the formation of a committee to study the feasibility of design-build and warranty contracting. This committee was to include members of the House and Senate, Department of Transportation officials, representatives from contractor 's associations, and a representative from the general public and would submit a report to the office of Budget and Program Planning. This bill was not enacted, but the Department continued their efforts by preparing a report containing specific suggestions as to how Montana could implement warranties on future highway construction projects (Stephens et al.2002).Like Texas and Montana, most states have made their own investigations into the use of performance-based warranties. Generally, state highway agencies have worked with research teams, contractors and industry associations to extensively evaluate the feasibility of warranted projects. Although sometimes a political push may be needed to encourage the use of innovative methods, states, which begin researching new ideas on their own, may have more time to carefully select the best use for these innovations. As exemplified by Ohio, who found it infeasible to meet existing legislative mandates, states may have to amend the legislation later, indicating the legislature may not be best suited to make the first move.Statutory AssessmentAs pointed-out earlier, statutes regarding public work, public transportation, state government, and other related statutes should be evaluated in terms of the legal environment of the warranty contracting. Three related major legislations are project delivery, public bidding procedures, andbonding requirements.Legislation regarding Design-Build Project DeliveryHistorically, contractors are told what materials to use and how to use them in the construction project. State personnel oversee the construction and perform continuous quality assurance testing to ensure the contractor is following the specifications. Legislation may restrict a state to this process, which does not allow for the increased contractor control that use of a warranty may dictate. Several transportation agencies have explicit authorization for design-build contracting methods. For instance, Ohio Revised Code *5517.011 allows for a value-based selection process where technical proposalscan be weighted and the bid awarded to the contractor with the lowest adjusted price. These projects may be limited to a specific type of construction, such as tollway or bridge projects, or by the dollar amount of design-build contracts that may be awarded annually. Oregon Revised Statute *383.005 allows for tollway contracts to be awarded considering cost, design, quality, structural integrity, and experience. Wisconsin Statute *84.11(5n) allows for certain bridge projects to be bid under design-build after a prequalification process, assessment of a variety of Transportation and the governor. In Ohio, the Revised Code *5517.011, however, limits design-build contracts to $ 250 million biennially.Other statutes are more general, simply stating that public agencies are permitted to usedesign-build contracting methods, e.g. Idaho Code * 67-2309. In state where design-build contracts are specifically outlawed by statute(e.g. Tenn. Code *4-5-102), the agency has few options. In Texas, where design-build is not allowed, the agency has implemented a rigid, multistep prequalification process in an effort to factor in advantages one contractor may have over another, when still complying with the traditional design-bid-build laws (Strayhorn 2001). Design-build and warranties seem to go hand-in-hand, allowing less agency interaction from the beginning of the project and more confidence in the contractor 's ability to fulfill the warranty requirements. However, the proper statutes need to be in place for an agency to utilize this innovative contracting method.Legislation of Public Bidding ProceduresThe use of warranties and other innovative contracting methods may not fit cleanly within existing bidding procedures for public contracts. If the request for proposals details the project in terms of performance based specifications, bidding laws must account for the different methods and materials proposed by bidders. Traditionally, bidding laws require an agency to solicit bids through a competitive, sealed bidding process and award the contract to the “lowest responsible bidder.”Exceptions to the lowest bidder rule are sometimes built into statutes, but the more common exceptions only allow an agency to reject all bids if they are all unreasonable or when it is in the interest of the awarding authority to reject all bids, e. g., Alabama Code *39-2-6(c). However, the lowest responsible bidder language presents a way through which a state may avoid contracting with simply the lowest pecuniary bidder, which may better serve the goals of the project.Application of Assessment Framework to AlabamaThe proposed assessment framework was used to investigate the laws and regulations necessary in Alabama to successfully incorporate warranties into current contracting practices and at the same time, avoiding litigation. Currently, the state of Alabama has no legislative directive requiring the use of warranties. Therefore, the Alabama DOT, working with the surety industry, contractors and academics, will need to develop a plan if they intend to implement warranties. Indoing so, the agency should look at statutes which may impede the use of warranties. Please refer to the Appe ndix for a list of Alabama Statutes.为保证合同的法律环境介绍在美国国务院，国道机构正在受到越来越大的压力，以提供持久的运输基础设施和功能迅速在最佳生命周期成本。
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Synchro在交通控制与设计中的应用在城市的较小的区域内，可以对区域内的所有交叉口进行控制;在城市较大的区域，可以对区域进行分区分级控制。
分区的结果往往使面控制成为一个由几条线控制组成的分级集中控制系统，这时，可认为各线控制是面控制中的一个单元；有时分区的结果是成为一个点，线，面控制的综合性分级控制系统。
现在对城市道路进行区域协调控制就是将其划分为多级多个信号控制子区，对信号子区进行协调控制，优化管理控制信号子区，然后对整个道路进行区域协调控制，达到整个城市道路优化的目的。
把城市道路划分为多个信号控制子区，也就是进行城市道路干线交叉口交通信号协调控制，把城市划分为多个主路控制，再把主路上各个交叉口进行联动控制，同时，对单个交叉口信号控制优化的同时需要考虑主路上下游各个交叉口的联动控制。
主路上的各个交叉口按照设计的信号配时方案进行运行，使车辆进入城市主干道交叉口时，不至经常遇到红灯，称为城市主干道交叉口信号协调控制，称为“绿波”信号控制。
城市单点交叉口作为城市交通网络中的重要组成部分，作为城市道路交通问题的关键点。
对城市单点交叉口，评价标准的参考指标：交叉口的通行能力、进口道的饱和度、道路交叉口进口道停车延误、交叉口进口道停车次数、进口道排队长度和汽车的油耗等。
交叉口定时信号控制配时方法在不断的改进之中，国内外大部分学者认为从不同的评价指标出发，可以采用不同的种优化算法寻求其它更合理的配时方法。
平面交叉口按交通管制方式可以分为全无控制交叉口、主路优先控制交叉口、信号灯控制交叉口、环形交叉口等几种类型。
主路优先控制交叉口，是在次路上设停车让行或减速让行标志，指令次路车辆必须停车或减速让主路车辆优先通行的一种交通管制方式。
交叉口是道路网中通行能力的“瓶颈”和交通事故的“黑点”。
国内外城市中的交通堵塞主要发上在交叉口，造成车辆中断，事故增多，延误严重。
如日本大城市中的机动车在城市中心的旅行时间约三分之一花在平面交叉口上。
同时，交叉口也是交通事故的主要发生源。
美国交通事故约有一半发生在交叉口；原联邦德国道路上的交通事故约有百分之三十六发上在交叉口，城市中的交通事故约有百分之六十到百分之八十发生在交叉口及其附近。
因此，交叉口这个交通事故“多发源”问题不能不引起人们的高度关注。
怎样对城市交叉口实施科学管理就是本节要讨论的问题。
实施管制的方式取决于交叉口的几何特征和交通状况目的是为了保障交叉口的交通安全和和充分发挥交叉口的通行能力。
本节主要以十字交叉口为主，讨论全无控制交叉口和主路优先控制交叉口，同时简要介绍现代环形交叉口的基本要点。
单个交叉口的控制策略会对其上游及下游道路交叉口的车流量产生很大的影响，上游和下游交叉口距离越近交通流量越大的情况下，影响会越大。
交通信号“点控制”就是把单独的交叉口拿出来进行单独的分析，对其进行单独的信号优化和道路控制策略，而不考虑该交叉口对其上下游交叉口的影响。
城市道路交通信号区域协调控制的就是研究在一个城市道路子区内，对各个道路交叉口进行的信号周期时长、交叉口的绿信比以及路口间的相位差进行优化，以减小交叉口的停车延误、提高城市路网的通行能力的交通区域信号协调控制方法。
随着城市道路区域信号协调控制理论的发展，研究者发现，可以把一个较大的城市的道路交通区域路网看成一个大的整体，对其进行交通信号协调控制及优化，由于道路路网及机动车流量的复杂性，但是对其优化结果对其通行能力的提高不是很理想。
因此，从20世纪70年代，许多研究者开始尝试将庞大、复杂繁琐的道路路网按照一定的原则和方法模型进行划分，划分成若干个信号控制子区，然后再对信号控制子区域内进行协调信号控制，用以提高城市里整个道路路网的协调控制效果。
目前，城市道路交通拥堵问题己经成为全国乃至全世界都普遍关注问题。
城市道路及交叉口作为城市交通道路的基本服务设施，主要包括道路交叉口与路段，其服务性能的良好运行直接影响到城市交通的正常运转。
城市道路交叉口是道路系统的重要组成部分，城市道路通过交叉口这个节点把各条道路互相连接构成城市的道路路网，来协调交叉口各个进口方向上的车流量需要；同时在城市道路网络中各种各样的交通流（机动车，非机动车，行人）在此相互交叉通过、分流转向，可见交叉口是城市道路网络最为重要的位置。
但交叉口也是交通堵塞和交通事故的多发地点。
城市道路运输机动车的效率、道路安全度、交叉口通行能力、道路的服务水平对环境和能源的影响基本上取决于城市道路交叉口的通行能力。
在对城市道路交叉口中控制和优化中最为常见的是信号控制，在信号控制中单点信号交叉口是城市道路控制与优化的基础。
对城市道路交叉口进行科学合理的信号控制与优化，是提高城市交叉口的交通安全和通行能力、减少交叉口停车延误的有效措施，可以缓解城市拥堵的交通问题。
对城市道路交叉口信号进行控制优化的方法模型进行说明，介绍了交通信号灯控制的基本方法，熟悉介绍交通信号管理软件synchro的相关功能和仿真情况，以synchro为工具进行城市道路区域的协调控制，对城市道路区域协调控制模型进行介绍！以呼和浩特城市道路为例，通过对呼和浩特道路现状交通的分析调查，运用交通管理软件synchro进行仿真，通过对仿真结果的分析结合呼和浩特现在的道路状况，得到现状道路所存在的交通问题，通过对问题的分析，提出相应的优化方案，然后运用synchro对优化后的交通情况进行仿真，对比评价仿真结果，提出优化方案。
对城市交通信号问题进行优化，挺高城市交通道路的通行能力！完善城市交通的基础设施！本论文通过对城市道路交叉口交通信号的控制的说明，介绍了交通信号灯控制的基本方法，引出了城市道路交通信号区域控制，通过对城市交通信号区域控制的介绍，提出了对城市道路交通信号区域进行分级控制优化的方法模型。
本论文通过对交通信号仿真优化软件synchro6.0各个功能的介绍，软件优化模型及各评价指标的计算方法与模型的相关介绍。
基于呼和浩特市新城区，以新城区新华大街为主干道进行城市道路主干道交通信号控制与优化仿真。
通过对新华大街与锡林郭勒北路，新华大街与迎宾北路，新华大街与呼伦贝尔北路各个交叉口交通信号配时方案，道路属性，交通量等进行调查，通过对调查数据进行处理研究，运用交通信号控制仿真软件synchro6.0进行交通现状的仿真，然后再对新华大街主干道信号配时方案进行优化，对优化结果进行仿真，进行评价然后进行优化前后的仿真对比。
说明道路主干道控制优化的优点。
由于本次设计时间较短，加上本人在这方面的学习研究还有待提高，所以本论文只能简单地介绍相关的设计方法和模型，对于更加复杂交错的交叉口还有待进一步的学习和研究。
总体来说， Synchro系统对信号交叉口的配时方案及优化程序主要针对交叉口信号周期时长、相位方案和交叉口绿信比等进行总体综合优化。
该系统能充分考虑到该区域道路的各项性质（交叉口范围内的公交站点、公共交通的影响，交叉口范围内的路边停车、自行车和行人等各种外在因素对交叉口通行能力和服务水平的影响，其适用能力强，是一种专业针对信号交叉口使用较为简便的信号控制优化配时软件。
道路交叉口停车计算与交叉口延误的计算方法相同。
在交叉口进口道产生停车延误的车辆数与排队车辆数相同，如上图中的Q。
同时Synchro系统认为10s 以内延误的车辆没有完全停车，对这些车辆，Synchro通过计算每个车辆每次在进口道延误的时间，对延误在10s以内的车辆按照定好的相应比例确定停车数。
由于新华大街各个交叉口相距很近，使得交叉口与交叉口之间的车容量较小，而且各个交叉口之间的信号灯周期时长不同，不能进行关联管理，亦使得新华大街不能进行绿波交通控制。
对各个交叉口信号周期进行优化后，可以显著提高交叉口的服务水平，且可以对新华大街主干道进行联动控制，大大的减小了新华大街主干道上的延误在这段时间里，我通过对交通信号管理与仿真软件 synchro的不断熟悉与运用，逐渐深入的了解到了交叉口交通信号对城市道路交通的重要性！交通信号对于缓解现在各个城市道路拥挤的重要性，在这段时间里，我通过对呼和浩特新城区新华大街主干道道路情况和各个交叉口的交通情况的调查与统计，发现可以运用交通信号管理软件synchro对各个交叉口进行优化仿真，可以使新华大街主干道进行“线控制",进而提高新华大街主干道各个交叉口的通行能力。
Synchro in traffic control and the design application In city of smaller area, within the area can be controlled all the intersection; In the city of large region, can region partition of hierarchical control. The division of the results often make level control into one by the few line of control the grading o f centralized control system, at this moment, you may think that makes the control is the surface control a unit; Sometimes the division of the results is to become a point, line, face the comprehensive control of hierarchical control system. Now on the city road for regional coordination control is dividing the multilevel more signal control branch area, the son of signal area for coordinated control, optimizing the management control signal branch area, and then to the road for regional coordination control to achieve the purpose of the whole city road optimization.The urban road is divided into more signal control branch area, also is the city road junction lines to the traffic signal coordination control, the city is divided into more massive control, and each intersection on running for linkage control, at the same time, to a single intersection signal control optimization and at the same time to consider all the linkage of the massive upstream and downstream intersection control. Each intersection running according to design signal timing formula for operation, make the vehicle into the city intersection, not often meet with red light, called city intersection signal coordination control, known as the "green wave" signal control.City single point as a city intersection traffic network in the important part of urban road traffic problems as the key point. City intersection of single point, evaluation standard reference index: crossing capacity, the import of saturation, the way the intersections, intersection delay import way parking import stops, import way way queue length and the car fuel consumption, etc. Timing signal intersection control timing method in continuous improvement in, most scholars think both at home and abroad from different evaluation index set out, can adopt different kinds of optimization algorithm for other, more reasonable timing method.According to the plane intersection traffic control way without control can be divided into the intersection, massive priority control signal intersection control, intersection, ring intersection of several types. Massive priority intersection control, is on the way in time set the right-of-way or slow down the right-of-way parking sign, instruction time road vehicles must stop or slow down to the right-of-way vehicles running a traffic control method. Intersection of road network traffic capacity is in the "bottleneck" and traffic accidents "black spots". The traffic jam main cities at home and abroad to the hair in the intersection, causing traffic disruption, more accidents, delay serious. Such as Japan cities in motor vehicle in the city center of about a third of the travel time spent on plane intersection. At the same time, the intersection of the traffic accident is the main sources. The United States about half the traffic accident happened in the intersection; The federal Germany on the road traffic accident about thirty-six percent to the hair in the intersection, city in the traffic accident happened about sixty percent to eighty percent in the intersection and its nearby. Therefore, the intersection traffic accident "was" not aroused people's concern. How to carry out the scientific management of city intersection of this section is to talkabout the problem. Implementation of the control mode depends on the geometrical characteristics of the intersection and traffic conditions the purpose is to ensure the intersection of traffic safety and and give full play to the crossing capacity. This section mainly intersections is given priority to, to discuss all to no control intersection and massive priority intersection control, and briefly introduced the basic points of modern ring intersection.The single intersection control strategy of the upstream and downstream will road intersection traffic produce very big effect, intersection upstream and downstream the closer the greater the traffic flow, the greater the effect will be. The traffic signal "point control" is to separate out the intersection of the separate analysis, and carry on the single signal optimization and road control strategy, and don't consider the intersection of the upstream and downstream the influence of the intersection. The urban road traffic signal control is the study of the regional coordination in a city way way zone, to each road intersections of signal period of how long, how intersection green than and between the letter at phase difference is optimized, to minimize the intersection delay parking, improve the urban road network capacity traffic signal control method coordination area.Along with the urban road area signal coordination control the development of the theory, the researchers found that, can be to a larger city road traffic area network as a great whole, the traffic signal coordination control and optimization, as a result of road network and the complexity of the flow of motor vehicles, but for the optimization results to the travel of the ability is not very ideal. Therefore, since the 1970 s, many researchers began to try to be huge, complex tedious road network according to certain principles and methods model division, divided into several signal control branch area, and then again to signal control subdomain coordinate signal control, to improve the way of city road network coordination control effect.At present, the urban road traffic congestion problem has been become the attention and to the world. City road and intersection traffic as a city of basic services, mainly including road intersection and sections, the service performance in good operating directly affect the normal operation of city traffic.City road crossing the road system is an important component of the urban road through the intersection nodes to the various factors of city road connect each other of road network, to coordinate each intersection on the direction of imported cars need; At the same time in the city road network all kinds of traffic flow (motor vehicle, the motor vehicle, pedestrians) in the cross each other through the shunt turned, visible intersection of city road network is the most important position. But the intersection is traffic and traffic accidents of the multiple sites. City road transport vehicle efficiency, road safety degree, intersection traffic capacity, the service level of the road to the environment and the influence of the energy basically depends on the urban road crossing capacity.In the urban road intersections control and optimization of the most common is the signal of control, signal control of a single point signal intersection control and optimization of city road is based. City road intersection of scientific reasonable signal control and optimization, is to improve the city traffic safety and the intersection traffic capacity, reduce the effective measures to stop intersection delay, can ease congestion。