NCDOT's Congestion Management Unit prefers the use of system analysis software for arterials and networks of single or multiple signalized and/or stop/yield-controlled intersections. The amount of time and effort required to code and characterize a facility in microsimulation environment could be prohibitive. Under certain conditions, the use of analytical and computationally efficient tools may be beneficial, provided that such tools are capable of “encapsulating" the stochasticity arising in real-world transportation demand-supply interactions.
What is unclear is under what conditions is microsimulation materially different (in terms of outcome) from analytical tools and what tradeoffs exist in the use of micro vs. macro models? Conditions may involve the facility type being modeled, location (urban vs. rural), under vs. oversaturated traffic conditions and duration of the analysis period among other potential factors. The proposed tools include TransModeler, VISSIM, Synchro, and SIDRA. Other tools such as HCM-Based HCS or ARTVAL will be used for verification purposes. Twelve real world facilities will be considered in this effort that will include conventional and unconventional interchanges, conventional and intricate signalized intersections, roundabouts and urban street arterials.
The objective of this study is to consider the trade-offs between the four models' accuracy, reliability and cost effectiveness when compared to empirical data benchmarks. Should NCDOT move towards the exclusive use of micro or macro tools, those tradeoffs will need to be quantified on a range of evaluation criteria. This project will not focus on qualifying or disqualifying certain software; rather it will identify potential use cases for each of the tools considered.