010 Estimating and Forecasting Transportation Metrics – Lessons Learned

A conversation between Dr. Laurence R. Rilett and Dr. Dr. Andrzej Nowak Transportation planners and engineers have recently begun to utilize traffic simulation models to estimate and forecast transportation operations and reliability metrics. For example, the Highway Capacity Manual, Sixth Edition: A Guide for Multimodal Mobility Analysis (HCM-6) has recently defined capacity and passenger car equivalents based on output from the microsimulation model VISSIM. The advantage to simulation methods is that the metrics, which may be based on measures of central tendency (e.g. mean, median), measures of dispersion (variance, percentile), or even a combination of other metrics (e.g. travel time index), may be easily calculated and/or estimated. As one example, many researchers over the past decade have focused on developing and estimating metrics related to network reliability and resilience. This talk will focus on a number of issues related to using simulation for estimating transportation metrics with a focus on model assumptions and model calibration.