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Synthesis of Safety Research Related to Speed and Speed Management - Turner-Fairbank.. Page 16 off 25 to reduce injury crashes in Boise. The STEP publicity program was designed to inform the driving public of hazardous road locations, the types of driver actions that made these locations unsafe, and the traffic enforcement that would be used to alleviate the problems at these locations. The PI&E program portrayed the Boise Police Department as genuinely interested in increasing public safety, as opposed to simply citing motorists and collecting fines. STEP advisory messages were broadcast twice a day over three local radio stations. The implementation of STEP in Boise was associated with a significant 17 percent reduction in the number of injury crashes; a non-STEP control area experienced no similar change. More important, the change in Boise was most dramatic following the delayed implementation of the STEP PI&E campaign (publicity began one month after the start of aggressive traffic enforcement). Besides the Boise STEP efforts, successful speed enforcement programs using speed indicators and photo-radar have been attributed to well-mounted PI&E pro-grams (Hamalainen and Hassel, 1990; Cameron, Cavallo and Gilbert, 1992). The Impact of Speed Enforcement on Crime The deterrent effects of police practices on crime have been a topic of research and debate for several years. The 1974 report describing the impact of the Kansas City Preventive Patrol Experiment (Kelling, et al., 1974) was an early evaluation of the effect on crime of in-creasing or decreasing police personnel. No significant differences in the incidence of crime, citizen fear of crime, or satisfaction with police services were found between Kansas City, Missouri, neighbor- hoods varying in levels of enforcement. The Kansas City study was criticized for only examining variations in force size and not taking into account the type of police strategies used in combating crime. In response to the Kansas City study, Wilson and Boland (1978) developed a model predicting that police techniques that maximize the level of interaction between the police and the community (termed aggressive policing) will result in a reduction in crime. To support their model, they examined the historical incidence of robbery in 35 large American cities and found that robbery rates were lower in cities in which more traffic citations were written (their measure of aggressive policing). Despite criticism of the measure of aggressiveness used by Wilson and Boland (Jacob and Rich, 1981), similar historical research by Sampson and Cohen (1988) supports the model developed by Wilson and Boland. Weiss, et al. (1993) employed quasi- experimental methodology to directly manipulate the level of traffic enforcement and measure its impact on local area crime. Local crime levels in areas treated with traffic enforcement were compared to locations where no enforcement took place. No relationship was found between traffic enforcement levels and the prevalence of crime in the experimental sites. While the researchers postulate that traffic enforcement may indeed have no impact on crime, they also recognize several flaws in their research that may have made such an effect undetectable. Stuster's (1995) study of municipal speed enforcement examined the effects of municipal traffic enforcement methods on a variety of dependent measures. In addition to measures of traffic safety, reported previously, the incidence of crimes in the special zones was analyzed for a control and two experimental communities. Overall, serious crimes (e.g., murder, rape, robbery, assault, burglary, larceny, arson, and motor vehicle theft) declined by eight per-cent in the special enforcement zones of one of the experimental communities, and by one percent in the other experimental community. Less serious crimes (e.g. drug violations, vandalism, disorderly conduct, and prostitution) increased by four per-cent in the comparison community's control zones. None of the changes in serious crimes as a whole was statistically significant, but both experimental communities experienced significant declines in the incidence of the larceny and theft. This is the one type of crime equally likely to occur during nighttime as well as daylight hours (i.e., when the special enforcement was conducted). Analyses found the 11 and 12 per- cent declines in larceny and theft to be statistically significant and attributable to the deterrence effects of the special enforcement programs; larceny/theft declined less than 2 percent statewide and increased by 4 percent in the control zones of the comparison community ENGINEERING MEASURES Traffic calming techniques are street design or regulatory features that cause motorists to be more attentive to their surroundings and to drive more slowly; some traffic calming techniques are designed to induce motorists to select an alternate route. Techniques range from the http://www.ntl.bts.gov/ntl/DOCS/speed/speed.htm 07/19/2000