Exploiting the Capacity of Managed Lanes in Diverting Traffic around an Incident

Abstract

This paper studies the potential benefits of traffic diversion in incident management for freeway operations of concurrent flow lane facilities. Techniques that exploit the capabilities of the component object module interface of the microscopic simulation tool, VISSIM, were devised for modeling freeway incidents and the implementation of diversion strategies. The potential for mobility improvement in general purpose lanes as a consequence of diverting traffic around an incident using existing managed lanes and the resulting degradation in managed lane performance are considered in a case study. Results from experiments employing the developed simulation tool show that the benefit to general traffic from implementation of a diversion strategy depends on the following factors: the location of the incident scene relative to the starting point of the diversion opening, the total length of access to the managed lane under the diversion strategy, incident duration, and number of lanes blocked (i.e., incident severity). When diversion implementation lags, travel time reductions achieved through diversion are diminished.