To simulate or not to simulate

A simple decision analysis framework is used to illustrate the key factors to consider in deciding whether or not to use microsimulation to estimate the effects of transportation projects. Microsimulation is useful if it 1) results in implementation of a worthwhile project that would not have been implemented without the simulation or 2) prevents implementation of a project that is not cost-effective that would otherwise have been implemented. Key factors to consider are 1) the magnitude of project benefits and costs, 2) the accuracy of the microsimulation model, and 3) the cost of the simulation.