The investigators (a) developed routines and logic to describe bus vehicle and pedestrian (object) movement; and (b) designed a user-interface for data input and output including background for animation (i.e., layout and editing features). In particular, the elements involving random variables such as vehicle arrival rates, dwell times, and pedestrian/passenger flow, that lead to nonrecurrent congestion were analyzed and defined in relation to the modules they fall into within the overall model. The investigators also incorporated high-performance graphics capabilities to the 2-D simulation and developed predefined 3-D views.
Tests were performed to determine the robustness and validity of the individual modules of the model. The first module, the graphics module, was tested to determine the flexibility of importing and editing site configurations, particularly with regard to changing dimensions and characteristics such as angles of bus bays and no-parking zones. The second module, the traffic/pedestrian flow module, was tested for the accuracy of event generation rates as well as for logic governing object movement. Typical Washington Metropolitan Area Transit Authority (WMATA) transit terminal operations at the Silver Spring Metrorail station bus loading area were used to test the ability of the model to simulate and animate the conditions. An expert review panel, including consultants and WMATA staff, reviewed and commented on the work and the applicability of the model.
WMATA and its planning consultants provided the necessary data and graphical backgrounds for the animation. A literature review of recent advances in traffic and pedestrian simulation principles and technologies was also conducted.