Simulation of ITS on the Irvine FOT Area Using 'Paramics 1.5' Scalable Microscopic Traffic Simulator: Phase I: Model Calibration and Validation

Problem

Intelligent Transportation Systems (ITS) appear to provide a set of intuitively promising tools to improve the increasingly complex and rapidly deteriorating transportation systems of today. Comprehensive research tools for quantifying the expected benefits from ITS are, however, still absent. In order to quantify potential benefits of a given Intelligent Transportation System, traffic simulators are needed that can be used to assess the benefits of ITS in the planning stages, as well as in the implementation stages as a way to generate and evaluate traffic scenarios, optimize control, and predict transportation network behavior. Paramics 1.5, developed by Quadstone UK, is an ITS- (intelligent transportation systems) ready microscopic traffic simulator. This research sought to evaluate Paramics 1.5 for its use in modeling intelligent transportation systems (ITS).

Method

An evaluation template containing a general and comprehensive list of requirements for this type of simulator was compiled. Then the evaluation template was applied to Paramics 1.5 to form a subjective evaluation of Paramics 1.5's capabilities and applications. Paramics 1.5 was then calibrated, validated, and evaluated using a model of the transportation network in Irvine, California, a network composed of a highly congested, non-grid arterials in a rapidly growing employment center. Another objective evaluation, calibrated from key driving behavior parameters using real traffic data from the California Testbed, headquarted at the University of California, Irvine, was also conducted. Of specific interest were the car following and lane changing models of Paramics 1.5.

Findings

A list of requirements for a traffic flow simulator to successfully model ITS was developed. Paramics 1.5 proved to be an excellent shell or framework for a comprehensive and extensive transportation simulation laboratory. Paramics 1.5 offers two very important features: high performance and scalability. Paramics 1.5 also offers very plausible detailed modeling for many components of the envisioned ideal simulator. However, Paramics 1.5 also proved to have some limitations which are discussed in detail in the report. To deal with these limitations, improvements are suggested including modifications to the software itself and maturation of the Application Programming Interface (API), one of Paramics 1.5's most important capabilities. A comprehensive API for Paramics 1.5 would allow user modification and customization of the program to overcome many of the current limitations. Paramics 1.5 performed well during validation on a freeway link. However, on a full network, the vehicle release mechanism showed some time lag releasing demand onto the network, probably due to stacking of vehicles in memory before adequate headways are found on the road to release the vehicles. Although the problem itself is simple, its effects on the results were notable.