This paper describes the development of a microscopic simulation model purely from a traffic engineering point of view, to perform numerical analysis on the bus chaining phenomenon observed in traffic congestion. Bus chaining creates impatience among passengers, and is one of the greatest problems faced by a bus scheduler. The simulation study was performed to understand why bus chaining occurs, when it is likely to occur and whether it is possible to eliminate it. This model has been developed using a set of general purpose subroutines of the ATRAS (Automobile TRAffic Simulator) such as the Road Element, the Intersection Element and the Vehicle Generating Point. Although the simulation model is microscopic, the validation and verification procedures employed in this research are macroscopic. In the simulation process, since random numbers play a significant role, tests for randomness are inevitable. Surrounding traffic volume and the number of waiting passengers at bus stops are the key variables considered in the analysis. Simulation results show that the amount of bus chaining increases with the increase in the number of waiting passengers, even at a comparatively low volume of traffic. However, if the number of waiting passengers is increased, a high volume of traffic does not increase the bus chaining. Β©1997 by John Wiley & Sons, Ltd.