Evaluation studies showed that roadways equipped with automated speed enforcement can reduce the number of speeding vehicles by 27 to 78 percent.

Experience with automated speed enforcement in the other countries to support deployment in the United States.

Date Posted
04/22/2002
Identifier
2007-B00490
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Feasibility of Real-Time Remote Speed Enforcement in Work Zones

Summary Information

This study examined the use of automated speed enforcement (ASE) to enable police officers to monitor work zones from remote locations, and not be endangered by limited lateral space, limited sight distance, and the presence of barriers.

The ASE system was built using off-the shelf technology. A laser speed detector unit (LIDAR) was mounted on top of a high-resolution 300 mm digital camera. Computer programs were used to automate data acquisition and image storage processing based on preset speed limit threshold settings. Real-time images of speeders were transmitted via broadband wireless communications to law enforcement personnel positioned safely downstream. The communications system was able to transmit data up to 1.5 miles away from the work zone.

The overall objectives of study were to:

  • Determine whether a remote enforcement system was technically feasible
  • Assess whether vehicles could be correctly identified downstream
  • Determine attitudes towards the system from the law enforcement community


Subsequent to the field data collection activities, interviews were conducted with law enforcement personnel focus groups. The purpose of these focus groups was to determine if officers felt that remote enforcement could be legally and practically implemented in Texas. The first focus group consisted of deputies from Harris County, Texas. These officers were actually involved in day-to-day enforcement of traffic laws. The second focus group consisted of Texas Department of Public Safety (DPS) personnel. These officers were in leadership positions within the DPS.

FINDINGS

Harris County law enforcement officers favored the technology and said the system could improve safety in work zones and on bridges with long narrow roadways. Some police officers noted, however, that image quality on the black-and-white displays made vehicle identification slightly more difficult, but the degraded image quality was not enough to prevent positive vehicle identification.

The Texas Department of Public Safety had a more cautious view. Some participants were concerned about the lack of a continuous recording that could track visual history from initial vehicle detection until the motorist was stopped. DPS officers indicated they could not be absolutely sure they were ticketing the proper driver if there was a gap in visual history of more than about one-minute. Officers felt that continuous real-time video recordings would provide better visual tracking and be more difficult to challenge in court.

In addition to prototype testing, this study provided the results of other ASE investigations. Even though these investigations were not able to conclude that automated speed enforcement reduced vehicle speeds in work zones, they did show how ASE was effective on residential roads and freeways, and that these benefits may apply to work zones as well.

The following data was derived from literature research presented in the study:

Automated speed enforcement has been used extensively in Europe for a number of years. In 1978, ASE units were installed on a high-accident portion of the German autobahn. Following the installation of the ASE system, 85th percentile speeds dropped by 45 km/hr (28 mi/hr) (ITE Journal, Vol. 68, No. 6). The yearly number of accidents was also reduced after the system was installed.

A study in the Netherlands evaluated the effects of ASE when combined with variable message sign warnings (Transportation Research Record 1560). This study found that average speeds were reduced by 5 km/hr (3 mi/hr) and the 85th percentile speeds were reduced by 8 km/hr (5 mi/hr). The percent of vehicles speeding declined by 27 percent after the system was installed. Norway began using ASE in 1988 and now has units on 336 km (209 mi) of road (Transportation Research Record 1595). The number of injury accidents on the portions of road with the ASE systems declined an average of 20 percent, and the total number of accidents on these sections declined between 5 and 26 percent.

Canada and Australia have both used automated speed enforcement. In Ontario, a one-year ASE pilot program reduced the number of vehicles exceeding the speed limit by 50 percent. The number of vehicles traveling at more than 40 km/hr (25 mi/hr) over the speed limit was reduced by 74 percent. In Australia, the percent of traffic exceeding the speed threshold for enforcement fell from 10.8 percent to 2.4 percent after the ASE system was implemented (ITE Journal, Vol. 68, No. 6).
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