Evaluation of Usability of Dial-a-Ride Systems by Social Simulation

Dial-a-ride systems attract great attentions as a style of new transportation systems for urban areas. While it is reported that such systems improve usability of bus systems when applied in a small town or area, it is not obvious how and under what conditions the system are reasonable in comparison to traditional fixed-route bus systems. We conducted several computer simulations of dial-a-ride and fixed-route systems to compare usability and profitability of both systems. Simulation results indicated that: (1) Usability of the dial-a-ride system with a fixed number of buses drops very quickly when the number of demands increases. (2) When we increase the number of buses proportionally to the number of demands, the usability of the dial-a-ride system is improved more significantly than the fixed-route system. (3) When frequency of demands is sufficiently large, the dial-a-ride system offers a reasonable solution from both usability and profitability perspectives.