路桥工程专业英语赵永平第四课赵永平翻译

南昌大学第四课Freeway and its Accessory Facilities高速公路及其附属设施

Text: Freeway Design

Reading Material: Freeway Accessory Facilities

Text

Freeway Design高速公路设计

Freeway are the highest form of arterials and have full access control. The full control of access is need for prioritizing the need for through traffic over direct access. A freeway’s primary function is to provide mobility, high operating speed, and level of service, while land access is limited. Access connections,where deemed necessary, are provided through grade separated interchanges.The major advantages of access controlled freeways are high capacity of the facility, high operating speeds, efficiency of the facility, and safety to all highway users.

高速公路干道和最高形式，有完整的访问控制。完整的访问控制是需要优先需要通过直接访问的流量超过。高速公路的主要功能是提供流动性，高运行速度和服务水平，而土地使用权是有限的。访问连接，在认为必要的情况下，提供通过分层interchanges.The的主要优点是访问控制的高速公路设施的高容量，高运行速度，效率的设施，所有公路使用者安全。

The major differences between freeway and other arterials include the following elements: grade separations at cross roads and streets; the grade separated cross road connections between the freeway and crossroad are accomplished through exit and entrance ramps; and full control of access. Expressways can be designed with both freeway and non-freeway design elements. The use of jughandle style interchanges and use of right turn channelization is not considered freeway design, but can be used in expressway design.

高速公路和其他主干道之间的主要区别包括以下元素：交叉道路和街道的立体交叉;分层交叉的高速公路和十字路口之间的道路连接都是通过出入口坡道和全面的访问控制。可以设计快速公路与高速公路和非高速公路的设计元素。不考虑使用jughandle风格交汇处右转和使用的信道化高速公路设计，但可以用于在高速公路设计

Urban freeways generally have more travel lanes and carry more traffic than rural freeways. Urban freeways can be eigher depressed, elevated, at ground level, or a combination of the above. Urban freeways usually have a narrower median than rural freeways and tend to have more connections than rural freeways.

Rural freeways are generally similar in concept to urban freeways, except that the horizontal and vertical alignments are more conservative in design. This level of design is normally associated with higher design speeds and greater accessibility to right of way. Due to the rural

nature, right of way is typically more available and less expensive. This allows for a wider median which improves the safety of the facility. In addition to the increase in safety of a rural freeway, the higher design speeds in a rural setting allow for greater capacity, a higher level of mobility, and potencially a reduced need for multiple lanes. Rural freeways are normally more comfortable from a driver perspective, and generally have lower maintenance costs. The sections below discuss the different design elements of urban and rural freeways.

城市的高速公路一般有更多的旅游专线，并进行更多的流量比农村高速公路。城市高速公路可以非此即彼郁闷，高架，地面水平，或上述的组合。城市的高速公路通常具有更窄的中位数比农村高速公路，往往有更多的比农村高速公路连接。

农村高速公路，城市快速路的概念大致相同，除了水平和垂直对齐方式都比较保守的设计。这个级别的设计通常是与更高的设计速度和更大的无障碍权利的方式。由于农村的性质，权利的方式通常是更容易获得和更便宜。这允许更广泛的中位数，从而提高了安全设施。此外在乡村的高速公路的安全性的增加，在农村设置更高的设计速度，允许更大的容量，更高级别的迁移率，需要为多个车道potencially减少。农村高速公路通常更舒适，从司机的角度来看，一般具有较低的维护成本。下面的部分将讨论城市和农村高速公路不同的设计元素。

1 Design Speed

In general, the design speed of freeways should be similar to the desired running speed during off peak hours, keeping in mind a reasonable and prudent speed. In some urban areas, with populations under 50,000, the posted freeway speed is 65 mph. In other more densely populated urban areas (over 50,000), the posted speed is 55 mph. Because of the different posted speeds, the design speed chosen may vary. In many urban areas the amount of available right of way can be restricted and achieving high design speeds can be very costly. In balancing the need for safety and providing a high speed facility with consideration for right of way costs, the design speed for urban freeways shall be a minimum of 60 mph. For those sections of freeway, in which a 60-mph design speed is recommended by the Project Team, approval by the Roadway Engineering Manager is required.

1设计速度

在一般情况下，高速公路的设计时速应该是类似于所需的运行速度在非高峰时段，同时要注意合理和审慎的速度。在一些城市地区，人口5万，发布的高速公路速度为65英里。在其他人口较稠密的市区（超过50,000），车速为55英里。因为不同的发布速度，设计速度的选择可能会有所不同。在许多城市地区的金额可以限制可用的路权，并达到设计速度高，可以是非常昂贵。在平衡安全需要和权利的方式成本代价提供高速度设施为城市快速路，设计行车速度应至少60英里每小时。对于这些高速公路路段，其中一个60英里每小时的设计速度，建议由项目团队，巷道支护工程经理的批准是必需的。

In mountainous terrain it can be very difficult to achieve high design speeds due to horizental and vertical limitations of the terrain. It is important, though, to design freeways, urban and rural, that provide a consistent roadway for drivers. Due to terrain limitation the design speed of rural freeways in mountainous terrain shall be a minimum of 60 mph.

在山区，它可以是非常难以实现的高的设计速度，由于地形的horizental和