NSF/USDOT Collaborative Proposal: Methodology for Calibration and Validation of Traffic Simulation Models

Northeastern University, Boston MA

Investigators

Abstract

Traffic simulation is a critical methodology for the analysis of complex transportation systems and evaluation of new technologies and concepts. Modern traffic simulation tools are a synthesis of a number of individual models, interacting in complex ways. These models capture traffic dynamics and network performance on one hand, and travel behavior on the other. Despite the importance of traffic simulation models, both in research and practice, systematic procedures for their calibration and validation are very limited. The objective of this research is to develop the basis for scientific and rigorous approaches to the calibration and validation of traffic simulation models using readily available data, e.g., loop detector counts, speeds, etc. The calibration and validation approaches to be developed recognize the aggregate nature of the available data (which makes the error associated with various components of the simulation model difficult to isolate); and the complex, large-scale nature of the applications. The research builds the required methodological foundations from diverse fields such as, stochastic optimization, statistics, traffic flow theory, and travel behavior and uses empirical analysis to provide support for theoretical developments. Important activities of the research include: Development of a rigorous modeling framework for calibration and validation. Exploration of algorithmic and computational aspects of the proposed solution approaches. Identification of appropriate statistical validation techniques, applicable to the type of data available for validation of traffic simulation models and consistent with the characteristics and properties of the measures of performance of interest. Identification of long-term research directions that will eventually lead to practical tools for calibration and validation. Empirical analysis to assess the validity of the proposed approaches. Successful completion of the research will have important broader impacts. Without appropriate validation and calibration, conclusions regarding new systems and designs can be erroneous with serious consequences in terms of deployment cost and time, and overall assessment of their value. Improvements in the accuracy of traffic simulators and the validity of the conclusions reached through simulation will result in the minimization of the risk involved in the deployment of new technologies and the development of appropriate risk mitigation strategies and better utilization of available resources. Case studies will be developed. The research results will be disseminated through scholarly journals, seminars and conferences as well as through a web page. The results will also be integrated into the curriculum at two universities.