A modelling procedure is presented to represent the effects on traffic flow when transit vehicles stop to load/unload passengers. This is accompanied by a decision model that dynamically sets traffic signals in response to upstream detection of mixed private and public transit traffic. Differetn priority lists are generated to reflect different relative priorities for various events such as transit activities or queue discharges. Then a number of candidate signal plans are generated, one for each different list of event-based priorities, such as serving a queue or ushering a transit vehicle to its loading place. A computer program, entitled SPPORT (Signal Priority Procedure for Optimization in Real Time) was written to generate and evaluate these plans, and to select and implement the one which would give the least weighted delay to vehicles and passengers. The application of SPPORT to carry out real-time control for the intersection of Queen Street and Bathurst Street in Toronto was simulated. Test results indicate that there is a substantial reduction in total delay to both private traffic and transit when real time optimization is applied with transit loading effects represented. Delays to both types of traffic are reduced a further substantial amount when transit priority is introduced.