Considering an incident management system (IMS), this paper focuses on how to use existed resources efficiently to reduce the average incident duration. Traffic Management Centers (TMC) have two ways to manage incidents, namely, waiting until an incident is detected and then dispatching a traffic flow restoration unit (TFRU) from the depot to clear them, or having TFRUs out running along specific routes and clear the incidents they run into. We examine the effects of these two options using computer simulation technology. Based on simulation results, response surfaces are constructed demonstrate the impacts of these two alternatives on the incident duration, and an equilibrium point between them is determined.