Knowledge Resources

Implementing variable mandatory speed limits on four lanes with the optional use of the hard shoulder as a running lane resulted in a 55.7 percent decrease in the number of personal injury accidents on a major motorway in England.(January 2011)

Collisions on I-5 in Washington State have been reduced by 65-75 percent in a 7.5 mile corridor where an active traffic management system was deployed.(November 19, 2010)

A Variable Speed Limit (VSL) system on the I-270/I-255 loop around St. Louis reduced the crash rate by 4.5 to 8 percent, due to more homogenous traffic speed in congested areas and slower traffic speed upstream.(October 2010)

Integrated Corridor Management (ICM) on the I-15 Corridor in San Diego yielded an estimated benefit-to-cost ratio of 9.7:1.(September 2010)

Implementing Integrated Corridor Management (ICM) strategies on the U.S. 75 corridor in Dallas, Texas produced an estimated benefit-to-cost ratio of 20.4:1.(September 2010)

New Jersey Department of Transportation enhanced incident management efficiency by using I-95 Corridor Coalition’s Vehicle Probe Project data, experiencing an estimated savings of $100,000 per incident in user delay costs.(August 12, 2010)

The St. Louis Motorist Assist program had a benefit-cost ratio of 38.25:1, with annual secondary crashes lowered by 1,082 and annual congestion costs lowered by $1,130,000.(February 2010)

Northern Virginia's freeway safety service patrol (SSP) had an estimated annual savings of $6.49 million in motorist delay and fuel consumption resulting in a benefit-cost ratio of 5.4:1.(2008)

The average duration of incidents assisted by the Northern Virginia (NOVA) Safety Service Patrol (SSP) was 17.3 percent shorter than the duration for matching incidents without NOVA SSP assistance.(2008)

In Scottsdale, Arizona, a speed enforcement camera demonstration program on a freeway decreased the number of target crashes by 44 to 54 percent, injury crashes by 28 to 48 percent, and Proptery Damage Only crashes by 46 to 56 percent.(November, 2007)

A multi-jurisdictional emergency response crew in the Phoenix metropolitan area provides services to six cities with a benefit-cost ratio of 6.4:1.(August 2007)

The benefit-cost ratio for the safety service patrol (SSP) in Hampton Roads, Virginia was 4.71:1.(2007)

The safety service patrol (SSP) in Hampton Roads, Virginia decreased the average incident duration by 70.7 percent.(2007)

The safety service patrol (SSP) in Hampton Roads, Virginia produced an annual benefit of $11 million in fuel savings and reductions in motorist delay.(2007)

In Broward County, Florida, the 2006 analysis for the SMART SunGuide TMC roadway and incident clearance times showed reductions of 18 percent and 4 percent respectively over 2005.(January 2007)

At the Breezewood Interchange on the Pennsylvania Turnpike, installation of a truck rollover warning system immediately reduced the occurrence of truck rollover crashes.(April 2006)

In Denver, Colorado, anti-icing on interstate freeways reduced snow and ice related crashes by 14 percent.(19 August 2005.)

Modeling performed as part of an evaluation of nine ITS implementation projects in San Antonio, Texas indicated that integrating DMS, incident management, and arterial traffic control systems could reduce delay by 5.9 percent.(May 2000)

Evaluation of freeway DMS integrated with incident management in San Antonio, Texas, found fuel consumption reduced by 1.2 percent; integrating the DMS with arterial traffic control systems could save 1.4 percent. (May 2000)

Modeling performed as part of an evaluation of nine ITS implementation projects in San Antonio, Texas indicated that users of an improved traveler information web site would receive annual benefits of a 5.4 percent reduction in delay.(May 2000)

Modeling performed as part of an evaluation of nine ITS implementation projects in San Antonio, Texas indicated that drivers of vehicles with in-vehicle navigation devices could experience an 8.1 percent reduction in delay.(May 2000)

In San Antonio, Texas, 60 percent of drivers of transit vehicles equipped with in-vehicle navigation devices reported that they saved time and felt safer.(May 2000)

Evaluation indicated that integrating DMS and incident management systems could reduce crashes by 2.8 percent, and that integrating DMS and arterial traffic control systems could decrease crashes by 2 percent, in San Antonio, Texas.(May 2000)

In San Antonio, Texas, focus group participants felt that DMS were a reliable source of traffic information.(May 2000)

In San Antonio, Texas, usage of a traveler information Web site increased at a rate of 19 percent per year and spiked during severe weather events.(May 2000)

In Japan, a field test found that conventional toll collection takes an average of 14 seconds per car, while electronic toll collection takes only 3 seconds per car.(October 1997)

In Japan, a real-time incident detection and warning system installed on a dangerous curve on the Hanshin Expressway decreased the rate of secondary crashes by 50 percent.(October 1997)

In Brooklyn, an incident management system on the Gowanus and Prospect Expressways used CCTV, highway advisory radio, dynamic message signs, and a construction information hotline to improve average incident clearance time by about one hour, a 66 percent improvement.(May 1997)

The delay reduction benefits of improved incident management in the Greater Houston area saved motorists approximately $8,440,000 annually. (7 February 1997)