Knowledge Resources

Nearly 92 percent of warnings issued to drivers by an improved prototype Lane Departure Warning System are valid.(March 2013)

Red light violation cameras significantly reduce rates of red light running at ticketed intersections and those in the same travel corridor.(January 2013)

Full deployment of mobility applications may be capable of eliminating more than 1/3rd of the travel delay that is caused by congestion.(12/10/12)

Right angle crashes were reduced by 86 percent, total crashes by 57 percent, and estimated severity costs by $268,900 in a two year analysis of red-light traffic signal enforcement in New Jersey.(November 2012)

HAWK pedestrian beacon shows 69 percent reduction in crashes involving pedestrians.(June 2012)

91 percent of volunteer drivers that tested V2V communications safety features indicated they would like to have these technologies on their personal vehicle.(05/21/2012)

Steering responsive headlight technology can improve driver visibility on inside curves and reduce "bodily injury liability" claims by 17 percent.(April 2012)

The Kansas City Scout program used ramp meters to improve safety on a seven mile section of I-435; before and after data indicated that ramp meters decreased crashes by 64 percent.(2012)

Vehicle speeds decreased significantly in work zones where DMSs were used to inform drivers upstream.(December 2011)

Casualty benefits from advanced emergency braking systems in passenger vehicles have potential benefit-to-cost ratios ranging from 0.07 to 2.78.(November 2011)

Weather Notification System issues on time alerts 88.9 percent of time, but message coverage remains incomplete.(August 2010)

Intersection-related crashes decreased 11 percent overall at signal controlled intersections in Texas after the installation of automated traffic enforcement systems.(June 2011)

Light vehicles that automatically activate in-vehicle alerts, seat belt tensioners, and braking systems can reduce fatalities by 3.7 percent.(June 2011)

Integrated Vehicle-Based Safety System use results in 48 percent reduction in lane departure rate for light vehicles, with similar trend for heavy trucks.(June 2011)

In Michigan, 8 of 108 volunteers who drove light vehicles equipped with an integrated crash warning system indicated the system prevented them from having a crash.(June 2011)

Smart Infrared Brake Inspection Systems identify trucks with faulty systems. Of the vehicles flagged as having thermal issues, 86 percent were found to have a violation and 83 percent of those vehicles were placed out-of-service.(06/01/2011)

Audible "slow traffic ahead" alerts can improve drivers' situational awareness and increase safety on freeways.(June 2011)

An overheight warning system at a CSX bridge in Maryland decreased the number of tractor-trailer incidents by 75 percent(04/02/2011)

Active and passive in-vehicle safety technologies are expected to decrease fatalities up to 16 percent.(April 2011)

Red light camera enforcement programs in 14 cities in the U.S. reduced the per capita rate of fatal red light running crashes by 24 percent.(February 2011)

Initial findings from a ramp meter evaluation in Kansas City were consistent with findings in other cities that show ramp metering can reduce crashes by 26 to 50 percent.(January 2011)

The conversion of HOV to HOT lanes on I-394 reduced mainline crashes by 5.3 percent.(23-27 January 2011)

Cordon pricing in Stockholm contributed to a 3.6 percent reduction in crashes.(2011)

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)

Benefit-to-cost ratios for six dynamic message signs on two freeways ranged from 1.38:1 to 16.95:1 based on total crashes; however, hazard warnings posted during incidents were ineffective at reducing secondary crashes.(12/17/2010)

NHTSA estimates that annual fatalities in backover crashes would be reduced by 95 to 112 fatalities and annual injuries by 7,072 to 8,374 injuries if all vehicles were equipped with rearview cameras.(December 7, 2010)

In 2009, the Washington State DOT Incident Response Team was able to clear 98 percent of incidents in under an hour and nearly three quarters in less than 15 minutes.(November 19, 2010)

Conversion of an HOV lane to a HOT lane in Washington State allowed for a 3 to 19 percent increase in speeds in general purpose lanes despite a 2 to 3 percent increase in volumes in the general lanes.(November 19, 2010)

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)

Variable Speed Limit System shows promise; crashes reduced to lowest level in a decade.(October 2010)

In-vehicle technologies that use automated braking to prevent rear-end collisions can reduce drivers injured by 19 to 57 percent.(October 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)

Total crashes per mile per year decreased by 28.84 percent on a corridor operating under SCATS adaptive signal control in Oakland County, Michigan.(September 2010)

Use of Low Cost Driving Behavior Management System (DBMS) reduces recorded safety events by 38 to 52 percent.(June 2010)

Vehicle-to-vehicle applications can have positive benefit-to-cost ratios at fleet penetration rates above 6.1 percent.(04/29/2010)

Field data collected over the last two decades show variable speed limit (VSL) systems can reduce crash potential by 8 to 30 percent. (03/01/2010)

In Marshall, MN, a deer detection and warning system reduced number of deer/vehicle crashes by 56 percent.(2010)

In Hennepin County, MN, an intersection warning system reduced traffic conflicts and received very positive feedback from the public.(2010)

In Hennepin County, MN, a public survey reported nearly 80 percent of respondents had improved awareness of approaching traffic after the installation of the intersection warning system.(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)

An Arterial Service Patrol deployed during the re-construction of I-64 in St. Louis had a benefit-cost ratio of 8.3:1, lowered secondary crashes by 183 per year, and reduced annual congestion costs by $1,034,000.(December, 2009)

Total crashes were reduced by 50-66 percent on bridge decks in North Dakota utilizing fixed automated spray technologies for anti-icing.(October 2009)

Automatic Crash Notification (ACN) systems can reduce road traffic deaths by 1.5 to 15 percent.(September 2009)

In fiscal year 2008/2009, the Miami-Dade Traffic Incident Management (TIM) Team reduced the average roadway clearance time by 11 percent from the previous year.(2009)

An enhanced Automatic Collision Notification System enables three quarters (75.9 percent) of injured occupants to be correctly identified as seriously injured, by using only data automatically collected and transmitted by the vehicles.(June 2009)

Implementing an enhanced Automatic Collision Notification (ACN) system in all passenger vehicles in the US could help improve outcomes for over 15,200 drivers each year involved in moderate to high severity crashes. (June 2009)

Simulated Rural Highway Driver Warning Systems (RHDWS) showed a potential reduction of critical events by 21 percent, a decrease of 71 percent for runoff-road crashes, and contributed to smoother driving on the curvy highway.(May 2009)

Field Operational Test of a Drowsy Driver Warning System shows users of the system to be less drowsy as measured by percentage of eye-closure. (April 2009)

Using Inspection Selection Systems (ISS) and out-of-service (OOS) history information provided by safety information exchange programs can lead to significant reductions in crashes injuries and fatalities due to heavy vehicles.(03/02/2009)

Nearly all respondents (98 percent) to a nationwide motor carrier survey reported that CVISN electronic screening improved shipping times and reduced turnaround time delays.(03/02/2009)

An animal detection system with the warning lights activated resulted in 1.52 mi/h lower vehicle speeds (compared to warning lights off) for passenger cars and pick-ups.(March 2009)

Through use of the Roll Stability Control (RSC) systems, it was estimated that between 1,422 and 2,037 combination vehicle rollover crashes in curves could be prevented, resulting in effectiveness rates of 37 percent and 53 percent, respectively.(February 2009)

An analysis of benefits and costs of Roll Stability Control (RSC) Systems for the trucking industry found benefits per dollar spent values of $1.66 to $5.34 with varying estimates of efficiency and annual VMT.(February 2009)

Forward collision warning systems have potential to prevent 23.8 percent of crashes involving large trucks.(2009)

The deployment of side object detection systems on 257 transit buses in two different transit agencies reduced the side collision rate per 100,000 Vehicle Miles Traveled by 0.186.(December 15 2008)

Mandatory dynamic automatic controlling Intelligent Speed Assistance (ISA) could reduce fatal crashes over the entire road network by more than 50 percent, whereas static informing ISA could still give a reduction of almost 20 percent.(November 2008)

Mandatory dynamic automatic controlling ISA (Intelligent Speed Assistance) could reduce fuel consumption and harmful emissions by 4 to 11 percent.(November 2008)

In Kalamazoo Michigan, the activation of the Dynamic Lane Merge System in a work zone reduced the number of forced merges seven fold and reduced the number of dangerous merges three fold.(October 2008)

In Little Rock Arkansas, 82 percent of the drivers surveyed agreed that the Automated Work Zone Information System improved their ability to react to slow or stopped traffic.(October 2008)

In Espanola, New Mexico the implementation of a traffic management system on NM 68 provided a decrease in total crashes of 27.5 percent and a reduction in vehicle delay of 87.5 percent.(September 2, 2008)

Users of Adaptive Cruise Control report they tend to change lanes less frequently when using the system, but many drivers are unaware of the limitations of technology.(September 2008)

In Miami-Dade County, ITS pedestrian safety measures showed an increase in pedestrian safety by significantly reducing drivers right on red violations from 40 percent to 13 percent and increasing drivers yielding to pedestrians by up to 92 percent.(08/25/08)

An Integrated Safety and Security Enforcement System (ISSES) for identifying high-risk heavy trucks was estimated to contribute to crash reductions between 63 and 629, personal injuries between 16 and163, and 7 fatalities per year.(31 January 2008)

A 33 percent mean reduction in risky driving behaviors was observed in a test involving 191 service drivers.(January 2008)

Use of In-Vehicle Data Recorder shows crash rate reduction of 38 percent (January 2008)

Increasing integration between AVL systems, components, and interfaces has improved the ability of transit agencies to collect data on location and schedule adherence; support operational control, service restoration, and planning activities.(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)

In the Netherlands, a five month field operational test (FOT) of 20 cars equipped with lane departure warning (LDW) systems found that the number of unintentional lane crossings decreased by 35 percent on secondary roads and 30 percent on highways due to the use of LDW.(9-13 October 2007)

Speed camera programs can reduce crashes by 9 to 51 percent. (September 2007)

A Maintenance Decision Support System (MDSS) used by MaineDOT aided maintenance crews by providing visual aids to track storms, recommending treatments, extending trend forecasts, and creating training opportunities.(September, 2007)

A Side Object Detection System (SODS) for transit buses was cost-effective with a baseline benefit-cost ratio of 1.43 and a ratio range of 0.37-3.55.(August 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)

In Florida, the addition of Open Road Tolling (ORT) to an existing Electronic Toll Collection (ETC) mainline toll plaza decreased crashes by an estimated 22 to 26 percent.(21-25 January 2007)

Evaluation data show that forward collision warning systems (CWS) alone, and CWS bundled with adaptive cruise control (ACC) and advanced braking systems (AdvBS) can improve safety for commercial vehicles.(21-25 January 2007 )

Trucks equipped with collision warning systems, adaptive cruise control, and advanced braking systems have the potential to reduce truck-initiated rear-end crashes by up to 28 percent.(1/5/2007)

In Oregon and Colorado, downhill speed warning systems decreased truck crashes up to 13 percent at problem sites.(31 October 2006)

At a tunnel in Pennsylvania, an overheight/overwidth warning system improved safety; occasional crashes demonstrate value of system and importance of maintenance.(31 October 2006)

In Georgia, the Navigator incident management program reduced secondary crashes from an expected 676 to 210 in the twelve months ending April 2004.(August 2006)

In Switzerland, an animal warning system installed at 7 sites decreased collisions with large animals by more than 80 percent.(August 2006)

While both cars and sport utility vehicles (SUVs) benefit from electronic stability control (ESC) systems, evaluation data suggest that the reduction in the risk of single-vehicle crashes was significantly greater for SUVs (49 percent) than for cars (33 percent). (13 June 2006)

In Myrtle Creek, Oregon, an advanced curve speed warning system installed on I-5 reduced the speed of 76 percent of drivers surveyed.(June 2006)

An infrared detection system deployed in a mobile van correctly identified vehicles that need to be taken off the road 44 percent of the time; an improvement over using random selection alone.(4/11/2006)

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)

An integrated system of forward collision warning and adaptive cruise control functions was projected to prevent about 10 percent of all rear-end crashes, and 10 to 20 percent of severe near-crashes.(April 2006)

In Oregon, approximately 90 percent of motorists surveyed indicated that they would slow down in response to messages displayed by an automated high wind warning system.(February 2006)

Initial research suggests that most drivers will respond to intersection collision warning systems and slow or stop appropriately.(22-26 January 2006)

Two surveys asked motor carriers what the motivation was for safety technology installation. A clear majority of the respondents indicated that crash reduction (68%) and lower insurance rates (52%) were key benefits.(22-26 January 2006)

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

Widespread deployment of integrated countermeasure systems could prevent over 48 percent of rear-end, run-off-road, and lane change crashes.(August 2005)

In Arizona, red light cameras reduced the occurrence of severe right-angle and left-turn crashes while the number of rear-end crashes increased.(June 2005)

In North Carolina, a work zone equipped with smart work zone traveler information systems observed fewer crashes compared to other work zones without the technology.(May 2005)

Cost-benefit analysis from 132 red-light camera treatment sites in California, Maryland and North Carolina showed a positive crash reduction benefit of approximately $39,000 per site per year when property-damage-only (PDO) crashes are included and $50,000 per site per year when PDO crashes are excluded.(April 2005)

An evaluation of electronic stability control (ESC) and crash data from the Institute for Traffic Accident Research and Data Analysis indicated that the crash rate for single-car crashes and head-on crashes decreased by about 36 percent where ESC was expected to be effective.(18 February 2005)

HAZMAT safety and security technologies can reduce the potential for terrorist consequences by approximately 36 percent.(11 November 2004)

Survey data collected from tractor trailer drivers with one to three years of experience driving with intelligent vehicle safety systems (IVSS) indicate that IVSS lowers their perceived workload by 14 to 21 percent over a range of driving conditions.(28 October 2004)

Based on all police-reported crashes in 7 states over 2 years, electronic stability control (ESC) reduced single-vehicle crash involvement risk by approximately 41 percent and single-vehicle injury crash involvement risk by 41 percent.(8 October 2004)

The Illinois DOT enhanced work zone safety on I-55 by deploying an automated traffic control system that posted traffic information and enforcement updates (number of citations issued) on dynamic message signs located upstream of the work zone.(October 2004)

A dynamic lane merge system deployed at a work zone outside Detroit reduced aggressive driving maneuvers.(October 2004)

An analysis of the effectiveness of electronic stability control (ESC) at reducing single-vehicle crashes in passenger cars and SUVs (1997-2002 crash data from five States) suggested that single-vehicle crashes were reduced by 35 percent for passenger cars and by 67 percent for SUVs.(September 2004)

In North Carolina, a wet pavement detection system on I-85 yielded a 39 percent reduction in the annual crash rate under wet conditions.(August 2004)

Signal retiming projects in several U.S. and Canadian cities contributed to a reduction in crash frequency.(April 2004)

In British Columbia, the City of Kamloops experienced a seven percent decrease in snow and ice-related crashes following the introduction of pre-wetting and anti-icing techniques.(2004)

In 2002 the Maryland State CHART highway incident management system facilitated a 28.6 percent reduction on the average incident duration leading to an estimated 377 fewer secondary incidents. (November 2003)

A variable speed limit system deployed at a work zone on I-96 in Lansing, Michigan contributed to a decrease in the number of high-speed vehicles in the work zone.(September 2003)

Intersection collision avoidance systems deployed at intersections with high crash frequencies or high rates of severe injury are projected to recoup initial costs within one year, through a reduction in crashes.(September 2003)

In-vehicle rollover advisory control warning messages are expected to prevent 20 percent of rollover crashes caused by excessive speed in curves, based on driving data collected during a Freightliner FOT.(September 2003)

Automatic anti-icing systems on bridges reduced crashes by 25 to 100 percent and benefit-to-cost ratios ranged from 1.8:1 to 3.4:1.(August 2003)

In Salt Lake City, Utah the ADVISE fog warning system tested on a two-mile section of I-215 promoted more uniform traffic flow, reducing vehicle speed variability by 22 percent while speeds increased 11 percent.(June 2003)

In Tennessee, a low visibility warning system installed on I-75 dramatically reduced fog-related crashes.(May 2003)

On the Køge Bugt Motorway in Copenhagen, Denmark, variable speed limits reduced vehicle speeds by up to 5 km/h and contributed to smoother traffic flow during peak periods.(8 April 2003)

In Great Britain, automated speed and red-light enforcement reduced the percentage of vehicles exceeding the speed limit by 58 percent, the number of persons killed or seriously injured by 4 to 65 percent, and the personal injury accident rate by 6 percent.( 11 February 2003)

An I-40 work zone in Arkansas equipped with an automated work zone information system had fewer fatal crashes compared to similar sites without the technology.(12-16 January 2003)

A nationwide survey evaluating overheight/oversize warning systems found that eight states that deployed active infrared light or laser activated warning systems had fewer overheight load strikes on infrastructure components.(12-16 January 2003)

In Baltimore, a "second train coming" warning system decreased the frequency of the most common risky behavior at crossings (i.e., drivers that crossed the tracks after the protection gates began to ascend from the first train before the protection gates could be redeployed for the second train) by 26 percent.(November 2002)

In Los Angeles, California, the installation of a "second train coming" warning system at a light rail transit grade crossing reduced risky behavior of pedestrians and surveyed pedestrians felt that safety was improved.(November 2002)

In Minneapolis-St.Paul, an evaluation of the effectiveness of ramp meters on four test corridors showed that the number of crashes recorded for the interim period with reduced ramp metering capacity was 15 percent higher that the average number of crashes measured for the previous fully metered periods. (10 May 2002)

An evaluation of CVISN technologies found that electronic screening techniques that promote compliance with commercial vehicle safety inspections could prevent thousands of truck accidents each year.(March 2002)

Evaluation studies in Canada, the Netherlands, and Australia showed that roadways equipped with automated speed enforcement can reduce the number of speeding vehicles by 27 to 78 percent.(13-17 January 2002)

A study of travelers on Snoqualmie Pass, WA found that DMS can decrease mean driving speeds and reduce accident severity.(December 2001)

In Colorado, a downhill truck speed warning system installed on a curved section of I-70 reduced 85th percentile truck speeds by 27 percent.(November 2001)

Automated enforcement at intersections in the United States reduced traffic signal violations by 20 to 87 percent.(13 August 2001)

Automated pedestrian detection at signalized intersections tested in three U.S. cities reduced the number of pedestrians who began crossing during the steady DON’T WALK signal by 81 percent.(August 2001)

During the first year of operations at the "Big I" work zone in Albuquerque, temporary traffic management and motorist assistance patrols reduced the average incident response time to less than eight minutes, and no fatalities were reported.(4-7 June 2001)

A model indicated that an advanced transportation management and traveler information system serving northern Kentucky and Cincinnati reduced crash fatalities by 3.2 percent during peak periods.(4-7 June 2001)

An anti-icing program implemented by the Idaho Transportation Department resulted in a 83 percent decline in winter crash frequency.(20 March 2001)

In Florida, the Orlando-Orange County Expressway Authority found that driver uncertainty about congestion at E-PASS toll stations contributed to a 48 percent increase in crashes.(March 2001)

Winter maintenance personnel indicated that road weather information systems and anti-icing techniques reduce the frequency of crashes and insurance claims. (March 2001)

When the ramp metering system on Minneapolis-St. Paul freeways was deactivated, crash frequency increased by 26 percent.(February 2001)

Automated red light enforcement at 11 intersections in Oxnard, California reduced crashes by 7 percent, decreased right-angle crashes by 32 percent, lowered injury crashes by 29 percent, and reduced right-angle injury crashes by 68 percent.(7-11 January 2001)

In Toronto, Canada, accident prediction models show that traffic-sensitive route guidance can increase crashes at low market penetrations and decrease crashes at higher market penetrations.(7-11 January 2001)

In Vantage, Washington the deployment of an automated anti-icing system on I-90 was projected to eliminate up to 80 percent of snow and ice related crashes.(7-11 January 2001)

In Brazilian cities, automated speed and red light enforcement lowered crash frequency by 14 percent, decreased crash injuries by 19 to 98 percent, and fatalities 7 to 83 percent.(2001)

An evaluation of infrared brake screening systems at weigh stations indicated the technology increased the percentage of vehicles placed out of service because of brake problems by 250 percent.(December 2000)

Adaptive signal control systems reduced vehicle stops by 28 to 41 percent; improve safety.(December 2000)

In Tennessee, a fog detection and warning system implemented in 1994 significantly improved safety as no fog-related accidents have occurred since implementation.(October 2000)

FleetForward Evaluation, Final Report.(October 2000)

An evaluation of work zone safety technologies in Texas showed that speed display trailers can reduce average vehicle speeds by 5 mi/hr and decrease the number of vehicles traveling at excessive speeds in rural work zones. (2000)

In San Antonio, a modeling study found that if traffic congestion were to increase by 25 percent, posting nearby railroad crossing closing delays on freeway dynamic message signs would reduce crashes by 8.7 percent.(October 2000)

An automated wet pavement warning system installed on a freeway ramp in Ft. Lauderdale reduced vehicle speeds by 10.2 mi/hr during heavy rain and by 4.6 mi/hr during periods of light rain. (6-10 August 2000)

In Denver, on-board silent alarms installed on RTD buses contributed to a 33 percent reduction in bus passenger assaults between 1992 and 1997. (August 2000)

A model found that coordinating fixed signal timing plans along congested arterial corridors leading into Seattle, Washington would help reduce the number of expected crashes by 2.5 percent and the frequency of fatal crashes by 1.1 percent.(30 May 2000)

In Nebraska, a portable speed detection and warning system placed upstream from an I-80 work zone decreased the highest 15 percent of vehicle speeds by about 5 mi/hr as vehicles approached the work zone lane merge area.(May 2000)

In a rural area of Virginia, a collision countermeasure system installed on a two-way stop-controlled intersection reduced vehicle speeds by 2.4 mi/hr, and increased the average projected time to collision from 2.5 to 3.5 seconds.(1-4 May 2000)

An automated enforcement system in Charlotte, North Carolina reduced red light violations by 75 percent and decreased associated crashes by 9 percent. (May/June 2000)

In Georgia, call boxes installed on a 39-mile section of I-185 were estimated to eliminate one injury per year, and one fatality every five years.(May 2000)

In Iowa, a CB radio alert system designed to warn truckers of slow moving maintenance vehicles on freeways effectively warned 39 of 59 truckers interviewed that remembered seeing the maintenance work in-progress.(May 2000)

In Greenwood, Nebraska a portable traffic management system designed to caution drivers of work zone activity and encourage use of alternative routes during periods of congestion increased traffic diversion by 4 percent.(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 1997, the Maryland CHART highway incident management program facilitated a 35 percent reduction in the average incident duration which led to an estimated 337 fewer secondary incidents. (May 2000)

An advanced curve warning system on an interstate route in northern California caused over 68 percent of drivers to reduce their speed. (April 2000)

Crash risk along a corridor in Arizona was reduced by 6.7 percent due to traffic signal coordination among two jurisdictions.(April 2000)

Automated red light enforcement in Fairfax, Virginia has reduced the crash rate by 35 percent. (16 March 2000)

Automated red light enforcement systems have reduced right-angle crashes by 32 percent in Victoria, Australia; and decreased crash frequency by 47 percent and red light violations by 53 percent in Howard County, Maryland.(January/February 2000)

A driving simulator study in Finland indicated that drivers cannot accurately assess road surface friction, thus the use of adverse road condition driver support systems can assist drivers in assessing adverse road conditions and increase safety and travel speeds. (2000)

A dynamic truck down hill speed warning system installed on I-70 in Colorado reduced the average speed of passing trucks by approximately 5.2 mi/hr. (15 December 1999)

Automated enforcement systems in Arizona, California, Maryland, and New York have reduced red-light violations by 20 to 60 percent and crashes by 22 to 51 percent. (December 1999)

A 1999 FHWA study suggested that lane departure warning systems have the potential to reduce road departure crashes by 10 percent for passenger vehicles and 30 percent for heavy trucks.(December 1999)

An automated enforcement systems in California decreased highway-rail grade crossing violations by up to 92 percent.(December 1999)

In Germany, a simulation study found that with 50 percent of vehicles equipped, the braking control features of a collision avoidance system would contribute to a 45 to 60 percent decrease in collisions when the leading vehicle brakes.( 8-12 November 1999)

In Michigan, an evaluation of adaptive cruise control indicated that the technology was effective at reducing risky lane changes in response to slower traffic, but took 0.3 seconds longer than manually controlled vehicles to respond to lead vehicle brake lights.(October 1999)

An analysis of the I-90 ramp closure system in Minnesota found benefit-cost ratios ranging from 0.13:1 to 3:1 with varying estimates of crash and delay reductions.(October 1999)

A six year evaluation of freeway ramp metering in Arizona found that that the system reduced sideswipe accidents on the mainline by smoothing traffic flow, but increased rear-end accidents on entrance ramps where vehicles were required to slow down or stop unexpectedly.(August 1999)

Advanced traffic management systems in the Netherlands and Germany reduced crash rates by 20 to 23 percent.(August 1999)

In-vehicle computer visioning technology designed to detect and warn truck drivers of lane departure and driver drowsiness reduced fuel consumption by 15 percent, increased safety, and provided drivers with more comfortable working conditions.(20 July 1999)

Vehicle-pedestrian conflicts were reduced by 89 percent in the first half of the crossing and 43 percent in the second half with automated pedestrian detection at intersections in Los Angeles, California; Rochester, New York; and Phoenix, Arizona. (Spring/Summer 1999)

During the initial deployment of electronic toll collection on the Carquinez Bridge (1996-1997) there was an increased number of crashes and personal injuries.(March 1999)

Automated red light enforcement reduced the number of violations by 42 percent at 5 intersections in San Francisco, California. (March 1999)

Speed-activated dynamic message signs with warning messages reduced vehicle speeds by 8 to 9 mi/hr; sustained effects for long-term work zones.(December 1998)

In Glasgow, Scotland a freeway ramp metering system installed at an entrance ramp to the M8 motorway reduced the frequency of early merging by 29 percent.(12-16 October 1998)

An automated speed enforcement system deployed in Korea reduced crash frequency by 28 percent and decreased crash fatalities by 60 percent. (12-16 October 1998)

Installing new traffic signals in Japan reduced crash frequency by 75 to 78 percent and upgrading existing traffic signals reduced accidents up to 65 percent.(March 1998)

There were 32 accidents along a transitway at the University of Minnesota before transit priority lights were installed, while no accidents were reported after installation of the lights.(2 February 1998)

Evaluation Results of Three Prototype Automatic Truck Rollover Warning Systems(11-15 January 1998)

In Colorado, a dynamic truck downhill speed warning system (DSWS) installed on I-70 decreased the number of accidents by 13 percent.(15 December 1997)

After a ramp rollover warning system was installed at three curved exit ramps on the beltway around Washington, DC, there were no accidents at any of these sites during the three year post deployment test period evaluated.(15 December 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)

Studies in six metropolitan areas of the United States and Australia, automated enforcement systems reduced red light violations by 20 to 60 percent, decreased right-angle crashes by 30 percent, and reduced crash injuries by 10 percent.(August 1997)

In Colorado, a down hill truck speed warning system installed on I-70 reduced runaway ramp usage by 24 percent and contributed to a 13 percent drop in crashes involving trucks and excessive speeds.(May 1997)

In the Minneapolis/St. Paul, a portable traffic management system installed at two interstate work zones improved safety by slowing approaching vehicles by 9 mi/hr and reducing speed variability by 70 percent. (May 1997)

In England, an variable speed limit system on the M25 freeway increases average travel times, but promotes proper following distances between vehicles and creates smoother traffic flow.(14 March 1997)

Following deployment of the TransGuide freeway management system in San Antonio, Texas, crash frequency was reduced by 41 percent and incident response time decreased by 20 percent.(12-16 January 1997)

In Norway, automated speed enforcement systems decreased injury accidents by 5 to 26 percent.(1997)

In Philadelphia, the Traffic and Incident Management System (TIMS) on I-95 contributed to a 40 percent decrease in freeway incidents and reduced the incident-severity rate by 8 percent.(January 1997)

In Orlando, a TravTek simulation study found that motorists that use navigation devices reduce their crash risk by 4 percent as a result of improved wrong turn performance and the tendency of the system to route them through higher class (normally safer) facilities.(January 1996)

A prototype CVO electronic screening and credentialing system deployed on two interstate corridors was projected to have a benefit-to-cost ratio of 3.6 over 20 years as a result of improved safety and productivity for agencies and commercial carriers.(1996)

In Finland, a road weather information system with variable speed limit signs was projected to decrease the average vehicle speed by 0.4 to 1.4 percent and reduce the annual crash rate by 8 to 25 percent.(December 1995)

Freightliner to Offer Collision Warning on New Truck Line(20 November 1995)

In Kansas City, a transit AVL system reduced the time required to respond to bus drivers' calls for assistance.(November 1995)

A 1995 North American survey of traffic management centers using ramp metering, identified reductions of 15 to 50 percent in freeway crashes.(June 1995)

Automated enforcement systems have reduced red light violations by 50 to 60 percent at two intersections in Fort Mead, Florida and Jackson, Mississippi.(17 March 1995)

Automated enforcement systems have reduced highway-rail crossing violations by 78 to 92 percent along two corridors in Los Angeles, California.(17 March 1995)

In London, England, automated speed enforcement systems have reduced speed by 10 percent, decreased all crash injuries by 20 percent, and reduced serious and fatal crash injuries by 50 percent. (March 1995)

On the A16 Motorway in the Netherlands, an automatic fog warning system prompted drivers to slow down by 8 to 10 km/hr and drive at more uniform speeds; however, during extremely foggy conditions the system increased the average vehicle speed by 31 km/hr matching the recommended speed.(1995)

At a work zone in South Dakota, a speed monitoring and display system reduced the number of speeding passenger vehicles and trucks by as much as 25 and 40 percent respectively.(1995)

Speed-activated dynamic message signs with warning messages reduced speeding vehicles by 50 percent or more in Virginia work zones. (August 1994)

Crash frequency declined when an advanced traffic management system and an advanced traveler information system were integrated in Oakland County, Michigan.(1994)

In Paris, France, incident management resulted in a nine-minute reduction in response time(1994-1998)

Institutional Issues Affecting the Implementation of IVHS Technologies to Commercial Vehicle Operations in the State of Indiana(1993)

In London, an automatic fog detection system that used freeway dynamic message signs to warn drivers of fog reduced traffic speeds by an average of 1.8 mi/h.(1993)

In Finland, a road weather information system was estimated to improve response times for road treatments, decrease the duration of slippery road conditions by 10 to 30 minutes, and eliminate 3 to 17 percent of crashes.(1993)

Increase of Traffic Safety by Surveillance of Speed Limits with Automatic Radar-Devices on a Dangerous Section of a German Autobahn: A Long-Term Investigation(1984)