Technical Summary


In October 1998, the Milwaukee, Wisconsin, Police Department was awarded the first federally-funded Aggressive Driving Demonstration Grant by the U.S. Department of Transportation, National Highway Traffic Safety Administration (NHTSA). This 18-month demonstration project was to study aggressive driving and provide information and enforcement results to law enforcement agencies across the U.S. The total grant of $650,241 included a local match of $173,716. Milwaukee competed with law enforcement agencies from 26 other metropolitan areas for this grant. The goals of the project were to develop and evaluate an innovative enforcement strategy to reduce aggressive driving and to develop and evaluate the effectiveness of public information and education programs to discourage aggressive driving.

The project was divided into three six-month phases. The first phase was devoted to gathering baseline data and developing the publicity plan and enforcement schedule. The second phase was devoted to conducting the enforcement effort and increasing public awareness about aggressive driving and the traffic violations that are generally associated with aggressive driving. The final phase provided time for the project to be evaluated and this report to be prepared.

On March 30, 1999, Milwaukee launched the Aggression Suppression Program, the enforcement and public information and education phase of this project. Coordinated by the City of Milwaukee Safety Commission, Aggression Suppression was a six-month program that combined 1) intensified general and targeted innovative enforcement, incorporating innovative enforcement strategies and technologies, with 2) publicity about the heightened enforcement and the dangers of aggressive driving.

NHTSA's primary objectives for the project were as follows:

Program Description

The program was planned and coordinated by the City of Milwaukee Safety Commission, which also functions as the Safety Division of the Milwaukee Police Department; the Safety Commission also was responsible for developing and implementing the public awareness efforts. An advisory committee included representatives from the City of Milwaukee Police Department; the Milwaukee County Office of the Sheriff; three suburban enforcement agencies; the Wisconsin Department of Transportation; the City's Infrastructure Service Division, Department of Public Works; and Preusser Research Group, Inc., which evaluated the program.

The program had the following elements:

Following the enforcement program kick-off, the remainder of the six-month enforcement program was organized into a series of three-week enforcement and publicity "sub-theme" campaigns. Each campaign focused on a specific traffic offense generally associated with aggressive driving, had a distinctive descriptive slogan, and was launched by a press conference hosted by one of the participating enforcement agencies. The publicity and enforcement efforts were designed to change the attitudes and behaviors of all drivers in Milwaukee. Enforcement was targeted to specific high-crash roadway corridors and intersections within Milwaukee County and to times of heavy traffic congestion.


The process evaluation indicated that the Aggression Suppression Program was exemplary in terms of planning, coordination, and implementation. The activities were well documented, and all evidence indicated that the program was fully implemented as planned, with strong "buy-in" from all partners.

All 20 enforcement agencies in the City and County participated in both the publicity and the enforcement efforts. To support enforcement of aggressive driving offenses, the project funded 5,700 patrol hours and 900 administrative and supervisory hours in the City of Milwaukee Police Department and 2,215 patrol hours in the Office of the Milwaukee County Sheriff. The law enforcement agencies of three suburban cities engaged in 1,200 hours of special aggressive driving enforcement, supported by State Highway Safety "Section 402" funding. Fifteen additional suburban law enforcement agencies voluntarily participated in the effort without special funding. A number of innovative enforcement strategies and technologies were tested. These included, for example, in-vehicle video cameras, plainclothes "spotters" placed at intersections, laser speed detection devices, laser devices equipped with technology to measure the distance between cars, electronic display boards to display traveling speeds, a specially developed roll call videotape, magnetic "Aggressive Driving Patrol" vehicle signs, and unconventional patrol vehicles.

Considerable earned media coverage was generated, especially at the outset, and numerous educational materials were developed and distributed. The series of sub-theme enforcement and publicity campaigns, and the rotation of the press conferences among the participating law enforcement agencies, helped to sustain media interest and to secure the "buy-in" of participating law enforcement agencies. Without paid advertising, however, it is doubtful that the campaign would have been able to saturate the media market.

The program succeeded in targeting enforcement to certain locations and certain times. The program was clearly successful in broadening enforcement efforts to target a wide range of aggressive driving offenses in addition to speeding violations. Based on a comparison of the 1999 program period to the comparable six months in 1998, there were large percentage increases in the numbers of citations issued by the City of Milwaukee Police Department and the Office of the Milwaukee County Sheriff for non-speed aggressive traffic violations. (Note that these data do not include citations for alcohol-impaired driving, seat belt violations, or operating after revoked/suspended license).

Citations for Aggressive Driving Offenses
City of Milwaukee Police Department and
Office of the Milwaukee County Sheriff April September 1998, 1999
  1998 1999 % Change 1998/99
Office of the Milwaukee County Sheriff
Non-Speed Aggressive Traffic Citations 2,205 3,424 +55.2
Speed Citations 12,647 11,866 -6.2
City of Milwaukee Police Department
Non-Speed Aggressive Traffic Citations 9,528 12,378 +29.9
Speed Citations 13,994 14,376 +2.7

For the most part, the innovative equipment aided in enforcing aggressive driving offenses. The speed display boards, in-vehicle video cameras, and laser speed detection devices were well received by officers. Officers were less enthusiastic about distance-between-cars laser technology; the process to obtain accurate measurements of distances proved complex. Enforcement agencies identified strategies that were particularly effective, for example, the roll call videotape, distribution of flyers to persons receiving citations, intersection patrols, and rotating the specific offenses targeted.

With regard to changes in motorists' driving behaviors, videotaping traffic at 10 intersections targeted for special enforcement, and 10 comparison intersections, was a feasible method for measuring the extent of red light-running. The percent egregious red light-running (of light cycles observed) declined at the targeted intersections from 6.5% during the pre-program period to 4.9% during the mid-program period, but increased at the comparison intersections from 2.9% to 12.7%. The average percentage change at the targeted intersections was significantly different than the average percentage change at the comparison intersections. Although suggestive of program effect, this evidence must be viewed cautiously; enforcement was intensively targeted to these intersections, but heightened enforcement also occurred citywide.

The program was associated with declines in crashes. As shown in the table below, the overall level of crashes declined significantly in the City, and the reductions were greater on the roadway corridors targeted by special enforcement than on comparison corridors. Similar patterns were identified for multiple-vehicle crashes and for crashes occurring at intersections; in each case, overall crashes declined significantly citywide, and the reductions were greatest on the targeted corridors.

Police-Reported Crashes
Target and Comparison Roadway Corridors and Citywide
City of Milwaukee, April-September 1998 and 1999
1998 1999 % Change
Personal Injury or Fatality 2,915 2,723 -6.6
Total Crashes 8,632 8,217 -4.8
Target Corridors
Personal Injury or Fatality 372 330 -11.3
Total Crashes 902 791 -12.3
Comparison Corridors
Personal Injury or Fatality 245 242 -1.2
Total Crashes 648 634 -2.2

Self-reported measures of attitudes and behaviors remained relatively flat across three self-administered surveys of drivers. However, drivers in the mid-program survey were significantly more likely than drivers in the pre-program survey to believe that they would be ticketed for running a red light or running a stop sign. Drivers in the mid-program survey also were more likely to believe that running a red light or driving through a stop sign was always/nearly always a problem. The level of awareness of the specific campaign themes was relatively low in all three waves of the survey. However, statistically significant increases in the level of awareness occurred for the themes of Rude Attitude Patrol, Courtesy Patrol, Space Patrol, and the State's concurrent "Let It Ride" campaign. A much more intensive and/or much more focused publicity effort may be needed to produce greater changes in attitudes and behaviors, especially in a community such as Milwaukee with a long history of highway safety programs and strong enforcement.

In sum, the Aggression Suppression Program demonstrated the effects of targeted enforcement. More citations were issued for aggressive driving types of violations (that is, not just speed tickets were issued); motorist behavior changed at targeted intersections; and crash reduction was demonstrated citywide, with greater reductions on corridors with targeted enforcement. Future programs of this type would be enhanced if they could generate more visible and more focused media attention.


HS Form 321