Analysis of isolated traffic signal control systems

Intelligent Transportation Systems (ITS) are implemented for increase of efficiency and safety in transportation. This thesis focuses on the area of traffic signal timing operations which is one of ITS components. The first objective is to compare the Czech and the U.S. methods for isolated fixed time traffic signal control, using an intersection in El Paso, Texas, as the test site. The second objective of this thesis is to evaluate the U.S. actuated isolated timing plan and compare it against the Czech and U.S. fixed time controls. A microscopic traffic simulation model of the selected intersection is coded in VISSIM to perform the comparative evaluation of average delay at the intersection. Ring Barrier Controller (RBC) is an additional module in VISSIM helping to create and evaluate the actuated timing plan. This module also allows the creation and evaluation of Transit Signal Priority (TSP). As the third objective, a few different scenarios with different bus arrival times and bus headways are evaluated in RBC to show its impact on bus delay and average delay of other vehicles at the intersection. The results of simulation experiments show that, for the morning peak, noon time off-peak and after peak periods of a weekday, the Czech signal timing plans consistently give lower average intersection delay and better intersection level of service compared to the U.S. fixed time and actuated control plans. In particular, the U.S. methods have problems serving left-turn movements with high volumes. The advantage of the Czech design method lies in its split interval calculations which optimized the phase sequence. When TSP is implemented at this intersection, it reduces the average bus delay by at least 18 seconds/bus. The TSP strategy also reduces the delay of other vehicles sharing the same signal phase as the buses. However, it increases the delay of vehicles in other signal phases