The study discussed in this report assessed the impacts of a pilot Aggressive Driver Imaging and Enforcement (ADIE) program along the Capital Beltway in Montgomery and Prince George’s Counties, Maryland. The Beltway, circling Washington, DC, is a heavily traveled freeway with weekday volumes exceeding 200,000 vehicles at various locations. This study used motorist surveys and speed measurements to determine the safety impacts and public opinion of the imaging and enforcement system and a related media campaign carried out in November 1997, with system beginning operation in January 1998.

The ADIE system consisted of a specially trained police officer using several ITS technologies mounted in a dedicated police vehicle positioned at appropriate locations along the Beltway. The system included radar speed measurement and video data to allow the officer to identify aggressive drivers and trigger an automated camera that photographed both the entire vehicle and the license plate. Warnings were mailed to offenders, but no penalties were assessed during the pilot program.

Both the before and after surveys were distributed to residents in the vicinity of the Beltway, Commercial Vehicle companies operating on the Beltway, and truck drivers at a rest area near the I-95 and I-495 Interchange in Maryland. Approximately 4,000 copies of the survey were distributed in April 1997 and again after the system began operation, with approximately 1,000 surveys returned each time. Survey results indicate that the media campaign was effective in increasing motorists’ awareness of the aggressive driving problem, with the number of respondents indicating that aggressive driving was a problem increasing from 19 to 54 percent. Prior to implementation, 82 percent of survey respondents favored using video technology for traffic enforcement, while 86 percent favored its use afterwards. Despite their support for video enforcement, only 48 percent of those surveyed felt that enforcement actions against aggressive driving on the Beltway were effective. Ninety (90) percent of respondents to the second survey hoped to see improvements to the system.

The study analyzed speed data from automatic recording stations at three locations along the Beltway to assess the impact of the system on vehicle speeds. There was a significant reduction in the number of vehicles exceeding 60 mi/h (the Beltway speed limit is 55 mi/h) in March 1998 when compared to March 1997. Two of the three recording stations showed decreases while one revealed an increase in the number of vehicles traveling at more than 60 mi/h. Due to the incomplete development of the system, related frequent technical problems hindering its application, and the short duration of the study period, overall safety impacts such as any reduction in the number of crashes on could not be assessed.