英语翻译Highway capacity Capacity and levels of services A princ

英语翻译
Highway capacity
Capacity and levels of services
A principal objective of capacity analysis is the estimation of the maximum number of people or vehicles that can be accommodated by a given facility in reasonable safety within a specified time period .however ,because facilities generally operate poorly at or near capacity ,they are rarely planned to operate in this range .accordingly ,capacity analysis also provides a means of estimating the maximum amount of traffic that can be accommodated by a facility while maintaining prescribed operational qualities .
Capacity analysis is ,therefore ,a set of procedures for estimating the traffic –carrying ability of facilities over a range of defined operational conditions .it provides tools for the analysis of existing facilities and for the planning and design of improved or future facilities.
The definition of operational criteria is accommodated at each level.
Ideal conditions
Many of the procedures in this manual provide a formula or simple tabular or graphic presentations for a set of specified standard conditions ,which must be adjusted to account for any prevailing conditions not matching those specified .the conditions so defined are often ideal conditions .
In principle ,an ideal condition is one for which further improvement will not achieve any increase in capacity.Ideal condition assume good weather ,good pavement conditions,users familiar with the facility ,and no incidents impeding traffic flow .specific ideal conditions are identified in each chapter .examples of ideal conditions are given below for uninterrupted flow facilities and for intersection approaches.

公路能力 服务能力和水平 主要目的是分析能力估计最多人或车辆,一定能够在合理的安全设施,在指定时间.但是 由于经营不善或附近设施普遍能力,但很少有人打算在此经营范围.因此,分析能力,还提供了最大程度的方法,估计交通可容纳设施的规定,同时维持业务素质.分析能力,因此,一套程序,估计交通承受能力,确定对各种业务设施条件.它提供的分析工具和现有设施的规划、设计和改进未来的设施.定义是满足各个层次的业务标准.理想条件 许多程序本手册提供的公式或表格或图表简单的一套规定的标准条件,应加以调整,以考虑到这些配套条件不存在任何说明.条件理想的情况下,往往规定.原则上,这是一个理想的状况进一步改善起不到任何增加的能力.好天气状况理想假设,路面条件好、设施使用者熟悉、不阻碍交通的事件.理想的情况下,每年都确定了具体的篇章.下面的例子对不理想的情况下,对流通设施的交叉方式.