Modeling and Simulation of Unconventional Traffic Circles

Microscopic simulation tools have been gaining popularity among the traffic engineers. Enhanced inputoutput capabilities of these simulation tools allow engineers model and simulate complex transportation networks, and gather results relatively fast. However, extensive validation/calibration efforts are required to verify the credibility of the results of these simulation models. This paper deals with the development of credible and valid simulation models of two unconventional traffic circles in New Jersey, namely the Collingwood and Brooklawn circles. These two circles are modeled in PARAMICS simulation software. The model development and validation / calibration steps are presented in detail. PARAMICS is one of the few off-the-shelf simulation software packages that can model unconventional traffic circles. However, it is shown here that the default capabilities of PARAMICS are not sufficient to model statistically valid simulation models of these two unconventional circles. It is also shown that the use of Application Programming Interface (API) feature of PARAMICS is required to develop realistic models that can accurately represent drivers’ facility specific behaviors. A gap acceptance/rejection binary probit model based on the analysis of field data is developed and implemented using PARAMICS API. The differences between the simulation results of the API enhanced model and the default PARAMICS model are presented to demonstrate the importance of extending the existing default models and the careful validation/calibration using real-world data Finally, the sensitivity analyses of the developed simulation models are presented.