In the initial stages of road design it is usual for several alternative route proposals to be considered but only outline details of road center lines and estimates of speeds and flows are available.
第一讲 绪论
一.专业英语是什么（what）？ 2、特点 2.2 语法特点
祈使语句和公式化表达方式
在理论分析和公式推导中常采用Assume that…，Suppose that…，Let…等祈使语气表达 方式。
So, next let us look at how to use SYNCHRO to do signal timing and simulation work.
第一讲 绪论
一.专业英语是什么（what）？ 2、特点 2.2 语法特点
非人称的语气和客观的态度，常用It…结构
It is important, though, to design freeways, urban and rural, that provide a consistent roadway for drivers.
The most appropriate location, alignment, and shape of a highway are selected during the design stage. Highway design involves the consideration of three major factors (human, vehicular, and roadway) and how these factors interact to provide a safe highway. Human factors include reaction time for braking and steering, visual acuity for traffic signs and signals, and car-following behavior.
