| *TRAFFIC TECH* |
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|                | Technology Transfer SeriesNumber 109, November 1995 |

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## MUNICIPAL   SPEED ENFORCEMENT PROGRAMS EVALUATED

 

When a municipal police department   begins a concentrated speed enforcement program, we can expect to see more speeding   citations. The National Highway Traffic Safety Administration (NHTSA) wanted   to know whether cracking down on speeders would also reduce the number of crashes   that were related to speed and whether this kind of traffic enforcement has   a deterrent effect on criminal activity   in the vicinity of the enforcement. 

Three California communities participated   in a six month study. The police departments in Modesto and San Bernadino conducted   speed enforcement programs in 6 special enforcement zones within each community.   A third community refrained from implementing any special traffic enforcement   effort during this time and served as the comparison site. Officers in the two   study communities spent, on average, about 8 hours each week in each of the   special enforcement zones conducting radar and laser-assisted speed enforcement. 

To compliment the enforcement   programs, both Modesto and San Bernadino organized traffic safety program support   committees to elevate public awareness of the special enforcement efforts. The   committees were composed of the police manager, local leaders, and concerned   citizens and were chaired by emergency department physicians. The campaigns   included press conferences, posters, brochures, supermarket drop-ins, public   speakers, bus bench display advertising, media events, and TV and radio public   service announcements. 

The contractor collected data   on crashes, speed samples, and crime from each of the police departments and   a statewide reporting system. They looked at the incidence of injury, fatal,   and property damage only crashes in which unsafe speed, following-too-closely,   or right-of-way violation was the primary collision factor.

 

 

Speed   Related Crashes Decline 

In both study sites, speed related   crashes declined 11.3 and 1.1 percent, while increasing 3.4 percent in the comparison   community. The reduction in speed related crashes was statistically significant   in one of the experimental communities. During this time, unobtrusive measures   of vehicle speed found that the number of vehicles exceeding the limits declined   19 and 10 percent in the two study sites. In the comparison community, where   no special enforcement occurred, the number of speeders declined by only 3 percent.   

 

Certain   Crimes Decline 

The FBI categorizes crimes as   Part I and Part II. The 8 Part I crimes are the more serious and include homicide,   rape, robbery, burglary and breaking or entering, larceny-theft, arson, and   motor vehicle theft. The list of Part II crimes is more extensive and includes   forgery, vandalism, weapons carrying, and drug abuse violations. Both Part I   and Part II crimes were analyzed in this study. 

Overall, the more serious Part   I crimes declined by 8 percent in the special enforcement zones of one of the   study communities, and by 1 percent in the other. Part I crimes increased by   4 percent in the comparison control zones. None of the changes were statistically   significant.  

Looking at larceny-theft crimes   only, however, both study communities showed statistically significant declines.   Larceny is the only Part I crime that is equally likely to occur during daylight   hours as at night (when the special enforcement was conducted). Larceny and   theft declined 11 and 12 percent, compared to a statewide decline of only 1.7   percent and an increase of 4 percent in the comparison community. In addition,   Part II crimes declined by 9 percent in one of the study communities and this   change from the same six-month   period one year earlier was statistically significant. Similar Part II crime   data could not be obtained for the other study community. Part II crimes increased   by 8 percent in the comparison community.  

Traffic enforcement stops conducted   during the study resulted in more than 2,000 arrests for offenses   ranging from assault to misdemeanor and   felony warrants. 

Municipal speed enforcement programs   can have positive effects on public opinion, traffic safety, and crime. The   benefits obtained during the current   study include:

- Increasing public awareness and support for the special law enforcement     programs.
- Reducing the incidence of speeding and speed related crashes.
- Apprehending individuals who were wanted for outstanding warrants, or who     were observed conducting illegal activity, as a consequence of routine traffic     enforcement stops.
- Deterring individuals from committing crimes in the vicinity of the enforcement     effort.
- Achieving a 500 percent return in revenue for the cost of equipment and     officer time. 

For a copy of the 70 page report,   *Experimental Evaluation of Municipal Speed   Enforcement Program,* contact Police Traffic Services, NHTSA, NTS-41,   400 Seventh Street S.W., Washington, DC 20590, or send a fax to (202) 366-7721.

   

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 U.S. Department   of TransportationNational   HighwayTraffic   SafetyAdministration400 Seventh Street, S.W. NTS-33Washington, DC 20590

Traffic   Tech is a publication to disseminate information   about traffic safety programs, including   evaluations, innovative programs, and   new publications. Feel free to copy it as you wish.

If you would like to receive a   copy contact: 

Linda Cosgrove, Ph.D., Editor,     Evaluation Staff Traffic   Safety Programs(202) 366-2759