RSG has developed traffic microsimulation models since the early 1990s, when TRAF-NETSIM was the tool of choice. In the intervening years, RSG has developed capabilities in all of the major commercial software packages including TransModeler, VISSIM, Paramics, and SimTraffic. Our typical model is land use-based, meaning that traffic is generated from geographically specified land uses such as housing, retail, and other commercial employment. Models range in complexity, including single intersections, multiple intersections along a corridor, or subarea models including multiple land use “zones” with several routing alternatives.

RSG microsimulation models are calibrated to observed traffic engineering measures such as peak period queue lengths, saturation flows, and vehicle delays. Every model we develop is only considered usable for decision making after calibration to nationally-accepted standards is achieved (e.g., GEH statistic < 5 for 85% of the link counts).

RSG specializes in the estimation of vehicular emissions from a simulated vehicle stream. We have developed methods for linking traffic microsimulation models to EPA’s MOVES mobile emissions estimator by characterizing the vehicle trajectory information from the microsimulation model as an Operating Mode Distribution. Air quality performance measures, including the generation of NAAQS criteria pollutants and greenhouse gases — are increasingly important in validating CMAQ grants/projects and in evaluating alternatives within a transportation planning study.