Unconventional Traffic Signal Control and Simulation Simulation-Based Evaluation of Unconventional Traffic Control Methods

Abstract

The objective of this thesis was to evaluate alternative traffic signal-control strategies at the Ullevi intersection in Gothenburg. A microscopic traffic simulation model was developed in PTV VISSIM using observed traffic volumes, public transport operations, pedestrians, bicycle facilities, signal groups, and detector information. Three signal-control scenarios were evaluated under identical traffic demand conditions: existing VAP-based actuated control, a tandem pre-signal design, and a fixed-time signal-control strategy. The scenarios were compared using average vehicle delay, queue length, vehicle travel time, and pedestrian travel time. The results showed that signal-control modifications can improve intersection performance without major physical infrastructure changes. The Tandem pre-signal technique showed an improvement in traffic flow on some approaches by using an upstream signal to organize before they have entered the main intersection. Whereas the fixed-time technique proved to be reliable and more consistent in dealing with many movements, including pedestrians crossing the road. Each solution, however, involved its own drawbacks, and they had different effects on different groups of road users as well as traffic as a whole. Overall, the results indicate that the signal control strategies used do not perform well under all conditions. The suitable approach depends upon practical priorities of the intersection and trade-off between the traffic movement and different user groups.