A Simulation Model for Transit Service Unreliability Prevention Based on AVL-APC Data

A stochastic simulation model using archived automatic vehicle location (AVL) and automatic passenger count (APC) data to simulate a fixed transit route service and test preventive bus operation control strategies against unreliability was developed. In this model, the bus operation and passenger demand were simulated based on AVL and APC data, and the decision-making process of preventive strategies was involved. A case study of bus services on the Route 20 at Chicago Transit Authority (CTA) was performed to demonstrate and test the simulator. All the parameters for the simulator in this case were derived only from CTA's AVL and APC data. Preventive strategies on bus operation were triggered according to the prediction of unreliability. The simulation result showed that preventive control strategies were effective on preventing headway irregularity.