Heuristic Method Of Transit Network Design

Sophisticated transit network design results in higher ratio of transit model share and better transportation service level. The main task of transit priority is design transit network faces users, namely minimize users travel cost which measured by travel time. The travel time in the transit network includes in-vehicle travel time, waiting time, transfer time and transfer penalty.The main time components in the transit network are in-vehicle travel time which related to network configuration and waiting time which related to frequency on each route. Increasing in-vehicle travel time will result in waiting time decreased, and decreasing in-vehicle travel time will result in waiting time increased. The essential of this study starts from the minimum in-vehicle travel time network, and then increase in-vehicle travel while decreasing waiting time by the feedback process to reduce user total travel time.This study presents Heuristic Method of TRAnsit Network Design (Hem-Trand in brief) which aim is minimizing total travel time for transit network. Hem-Trand designs transit network configuration and frequency on each route synchronously.Hem-Trand consists 4 procedures, including network generate procedure (NGP in brief), network analysis procedure (NAP), network optimal procedure (NOP) and transit terminal setting (TTS). A feedback mechanism followed for optimizing network. NGP initializes transit network configuration, in which the in-vehicle travel time is minimal and direct ratio is maximal; NAP sets the frequency on routes and reduce number of routes by 0-1 assignment and calculates evaluate indexes about network; Finally, Total Travel Time decreased and physical configuration changed by NOP; Guideline for the location of terminals is given by TTS. Feedback mechanism is a procedure of distribute the passenger flow again after the network physics configuration changed until the user's total travel time un-decreased and frequency convergence.The example presents the result by Hem-Trand is more optimal than other method in the minimum user's total travel time and the direct ratio.