The safety service patrol (SSP) in Hampton Roads, Virginia produced an annual benefit of $11 million in fuel savings and reductions in motorist delay.

Experiences of the Freeway SPP in the Hampton Roads, VA from 2005 to 2006

Date Posted
05/10/2011
Identifier
2011-B00681
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A Return on Investment Study of the Hampton Roads Safety Service Patrol Program

Summary Information

The safety service patrol (SSP) in Hampton Roads, Virginia, keeps travel lanes open for traffic by moving or helping to start stalled vehicles, removing debris from the roadway, and clearing traffic incidents. The Hampton Roads SSP assist motorists free of charge (to the drivers) by jump starting vehicles, providing gasoline, changing tires, etc. The SSP services approximately 80 miles on a 24-hour-per-day, 7-day-a-week basis. It patrols eight routes continuously and provides dispatch service on two routes. To justify funding the SSP, an evaluation was

A Return on Investment (ROI) study of the SSP in Hampton Roads, Virginia estimated the benefits attributable to the SSP from reductions in motorist delay, fuel consumption and emissions by analyzing traffic and incident data from July 1, 2005, through June 30, 2006 (1 year).

METHODOLOGY

The study compared the “begin” and “end” times of incidents on SSP routes to those on non-SSP routes (Virginia State Police (VSP) assist only). The study also used the Freeway Service Patrol Evaluation (FSPE) model to estimate incident-induced delay and associated delay savings attributable to SSP operations. The FSPE model employs deterministic queuing models to estimate motorist delay associated with queues that form during incident conditions. (Note that the results of the FSPE model did not account for day-to-day or seasonal variations. The study also did not attempt to estimate reductions in secondary incidents, or environmental or medical costs associated with SSP operations.)

Model parameters included:
  • Freeway capacity values and remaining freeway capacity factors due to incidents from the Highway Capacity Manual 2000
  • Emission rates from the Hampton Roads Planning District Commission (HRPDC)
  • Clearance time reduction data from an analysis of the VSP CAD and Virginia's Archived Data Management System (ADMS) databases
  • Travel time costs and fuel costs from the Texas Transportation Institute (TTI)
  • Occupancy rates (persons/vehicle) from the Federal Highway Administration’s (FHWA) 2001 National Household Travel Survey

FINDINGS
  • The estimated total delay and fuel benefits per year were $11,075,893.
  • The estimated savings in motorist delay per year were $455,856.
  • The estimated fuel consumption savings per year were $687,624.
  • The estimated emissions savings per year were 118,131 kg for reactive organic gases, 805 kg for carbon monoxide, and 12,115 kg for nitrogen oxides.
The table below shows the estimated annual savings in delay, fuel consumption, and emissions for different Hampton Roads SSP routes.
Route
Annual Delay Savings (vehicle-hour)
Annual Fuel Consumption Savings (gal)
Annual Emissions Savings
Reactive Organic Gases (kg)
Carbon Monoxide (kg)
Nitrogen Oxides (kg)
Naval Base/Reversible Roadway (I-64 and I-564)
138,843
209,434
5,521
246
3,690
Hampton Roads Bridge Tunnel
59,620
89,932
2,372
105
1,585
Coliseum A/Coliseum B
20,149
30,393
802
35
536
Highrise
21,683
32,707
863
38
576
Downtown Tunnel
21,434
32,331
852
38
569
Monitor-Merrimack Memorial Bridge Tunnel
10,669
16,097
424
18
284
2 Outer/2 Inner (I-264)
183,458
272,733
7,297
325
4,875
Total
455,856
687,624
18,131
805
12,115
Deployment Locations