Operation Feasibility Analysis of Freeway Diversion at Urban Network

An incident on urban freeway segment can result in serious traffic congestion along the freeway. As queue builds up along the freeway, both travel time and delay significantly increase upstream of the incident location. Using adjacent arterials as a diversion route can be one feasible alternative to the incident management plan since it can reduce traffic volume on the freeway and distribute exceeded demand to adjacent arterials. Increased traffic on the diversion route, however, can result in significant congestion along the arterials. Hence implementing appropriate signal timing plan on the arterials is essential. An operational feasibility analysis on a diversion route of urban freeway arterial in Springfield, VA was conducted for selected time of day conditions. Based on capacity analysis at critical intersection of the diversion arterial, critical demand volumes that can be handled by the network was computed for corresponding time of day conditions. In order to improve mobility on the diversion route, timing plan optimization and lane assignment change strategies were considered. For each time of day period, four timing plans including (i) current field timing plan, (ii) PM timing plan currently used for incident condition, (iii) new optimized timing plan without a lane assignment change, and (iv) new optimized timing plan with a lane assignment change were considered. Both travel time and delay were selected as network performance measure and they were estimated by VISSIM. The simulation results indicated that current PM peak timing plan, a designated signal timing plan for freeway diversion, did not improve mobility of the arterial network during diversion. It was found that newly optimized signal timing plan improved the mobility along the network in forward direction of the diversion route. The lane assignment change favoring diverting traffic also improved the mobility in forward direction of the diversion route.


  • English

Media Info

  • Media Type: Web
  • Edition: Final Report
  • Features: Figures; References; Tables;
  • Pagination: 20p

Subject/Index Terms

Filing Info

  • Accession Number: 01047343
  • Record Type: Publication
  • Report/Paper Numbers: UVACTS-13-00-84
  • Created Date: Apr 24 2007 1:30PM