it s characteristics of variety and openness to expansion ensure that it can easily keep pace with local development . a light rail rapid transit system with a monopoly right of way is the most flexible pre-set rail system in urban public transportation 一、号志系统及行控中心电脑系统为整体路网能否安全及顺利运转之重要关键之一,为系统扩建及整合过程中必须予以重视之一环。