The characteristics of heterogeneous traffic (with variation in vehicle length) are significantly different from those for homogeneous traffic. The present study describes an overview of the development and validation of a stochastic heterogeneous traffic-flow simulation model for an urban single-lane two-way road, with controlled intersection. In this paper, the interaction between vehicle types during manoeuvres at the intersection are analysed in detail. Two different motorised vehicle types are considered namely cars and buses (or similar length vehicles). A two-component cellular automata (CA) based model is used. Traffic flow data, captured manually by Dublin City Council at a local intersection, are analysed to give a baseline on how the distribution of short and long vehicles affect throughput. It is anticipated that such detailed studies will aid traffic management and optimisation strategies for traffic flow.