Mobility and Commute Disutility Effects of 511 Deployment in Salt Lake City, Utah

Abstract

The mobility and disutility-reduction benefits to users of the 511 advisory service currently deployed in Salt Lake City, Utah, were evaluated through a modeling study conducted using the HOWLATE (Heuristic On-Line Web-Linked Arrival Time Estimation) methodology. The benefits of the existing 511 advisory service to seasoned users of the service and the potential additional benefit to providing travel-time estimates via the 511 service were evaluated. Data were provided by the Utah Department of Transportation. Four types of commuters were modeled: (a) a nonuser, who ignored traveler information; (b) a 511 advisory user, who made use of the 511 advisory service currently available to commuters in Salt Lake City; (c) a 511 travel-time user, who made use of a hypothetical 511 service that provided travel-time estimates; and (d) a dynamic message sign (DMS) user, who made use of DMS deployed along 20 mi of I-15. Analysis showed that the existing 511 advisory service resulted in mobility and disutility-reduction benefits to seasoned commuters. Compared with the nonuser, the 511 advisory user was able to reduce peak-period late arrivals by 14%. By supplementing the existing 511 advisory service with DMS, late arrivals for current 511 advisory users can be further reduced by more than 10%. Providing travel times for the entire network over the 511 service can reduce peak-period late arrivals for current 511 advisory users by nearly 30%.