The design requirements were for three lanes of vehicular traffic and a single rail line in each direction.

这个设计要求在每个方向有三条交通车道和一条单线铁路线。

youdao

Based on the status quo and development trends of Shenzhen's rail transit system, this paper analyzes problems of the AFC system in the transition period from single-line to multi-line operations.

基于深圳市轨道交通现状及发展趋势，分析了AFC系统由单线运营转向多线运营所存在的问题。

youdao

Now,at last, the two coasts of the United States were united by a single line of metal rail.

VOA: special.2010.02.25