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EVALUATION OF SEMIMARKED POLICE VEHICLES

Research conducted by the Department of Law Enforcement in 1981 indicated that fuel consumption by patrol vehicles could be reduced by not equipping the vehicles with roof-mounted light bars (visabars). Savings were also projected through reduced equipment costs. Analyses of 1980 accidents involving marked and unmarked units indicated that no increase in accidents would result from removing the visabars. As a result of that research, in 1982 sixty semimarked (decal but no visabars), vehicles were assigned to personnel. Sixty marked units were also assigned. The units were paired so a marked and a semimarked unit were assigned to similar patrols. Data on accidents worked, reports completed, motorist assists made, and warnings issued indicates that the patrols were similar for the two groups in terms of work load. Data indicated that officers assigned semimarked units also achieved better fuel mileage, and incurred fewer and less severe accidents than marked units. They also achieved higher productivity with regard to the issuance of citations for speeding. The evaluation also included a survey of the perceptions of officers who were assigned semimarked units. Officers' perceptions with regard to semimarked vehicles indicated, among other things, a high degree of public approval, greater productivity, better performance (in terms of acceleration, fuel consumption and top speed), little impact on voluntary compliance, some degree of greater difficulty in vehicle recognition by the public, and, some level of reduced safety to the driver and the motoring public. For each of the five statements dealing with increased safety, at least half of the officers perceived "no difference" between marked and semimarked units. A significant percentage of the remaining officers saw a limited degree of decreased safety associated with semimarked units and a few saw a high level of decreased safety. However, these feelings on safety are put into perspective by the fact that 90 percent of the responding officers did not want visabars put on their semimarked units while only 6 percent (three officers) would make such a request. The remainder (two officers) were undecided. Also, as already stated, accident experience indicates a lower incidence of accidents for semimarked units than for marked units.

  • Corporate Authors:

    Illinois Department of Law Enforcement

    Administration Division, Bureau of Planning and Development
    Springfield, IL  United States 
  • Authors:
    • Stocia, T L
  • Publication Date: 1983-4-20

Media Info

  • Features: Appendices; Tables;
  • Pagination: 35 p.

Subject/Index Terms

Filing Info

  • Accession Number: 00380392
  • Record Type: Publication
  • Source Agency: National Highway Traffic Safety Administration
  • Report/Paper Numbers: HS-035 109
  • Files: HSL, TRIS, USDOT
  • Created Date: Dec 30 1983 12:00AM