Comparing with other rail transit systems, LRT (Light Rail Transit) has become a better alternative to construct MRT in Taiwan because of its advantages such as low cost, short period of construction, flexibility of ROW (Right of Way) and similar capacity with a medium-capacity transit system. So far there is no LRT in operation in Taiwan and most of research studies are full of discussions surrounding the signal priority for LRT at intersections. Therefore, the proposed simulation model in this study aims at providing better LRT operation strategies to ensure service quality in case of delay occurrences for scenarios with signal priority conditions and different types of ROW.
According to system functions and objects to be served, four types of agent including trains, stations, intersections and regions are classified based on multi-agent system. The functions are used to control train movement, determine waiting time at stations, give signal priority and implement operation strategies with concerned agents. The proposed LRT technical system architecture consists of wheel-rail rolling stock , GPS-based on board equipment, communication network among train, control canter and track-side facilities. Moving Automatic-blocking System (MAS) is also assumed as the train control system. Stations are classified into general stations and transfer stations. An absolute priority-based signal strategy will be used in this study, while partial signal priority strategy is only used in scenario analysis. Two types of operation strategy are recommended: one is to speed up to reduce running time and the other is to shorten headway.
Tamhai LRT Lines are taken as a case study. Two lines and two types of ROW are chosen in the simulation scenarios. Variables of scenario analysis include delay time at stations, signal priority strategies and thresholds of train dispatching. According to the results of simulations, total system delay has positive relationship with delay time at stations and thresholds of train dispatching if the operation strategy to speed up is used. However, total system delay has negative relationship with delay time at stations if the operation strategy to shorten headway is used. As a whole, total system delay has positive relationship with delay time at stations, thresholds of train dispatching and density of headway that can be shown in most of results of scenario analysis.