Feedback Interventions and Driving Speed: A Parametric and Comparative Analysis

Abstract

Five experiments were conducted to assess the effects of several variables on the efficacy of feedback in reducing driving speed. Experiment 1 systematically varied the criterion used to define speeding, and results showed that the use of a lenient criterion (20 km/hr over the speed limit), which allowed for the posting of high percentages of drivers not speeding, was more effective in reducing speeding than the use of a stringent criterion (10 km/hr over the speed limit). In Experiment 2 an analysis revealed that posting feedback reduced speeding on a limited access highway and the effects persisted to some degree up to 6 km. Experiments 3 and 4 compared the effectiveness of an unmanned parked police vehicle (Experiment 3) and a police air patrol speeding program (Experiment 4) with the feedback sign and determined whether the presence of either of these enforcement variables could potentiate the efficacy of the sign. The results of both experiments demonstrated that although the two enforcement programs initially produced larger effects than the feedback sign, the magnitude of their effect attenuated over time. Experiment 5 compared the effectiveness of a traditional enforcement program with a warning program which included handing out a flier providing feedback on the number and types of accidents occurring on the road during the past year. This experiment demonstrated that the warning program produced a marked reduction in speeding and the traditional enforcement program did not. Furthermore, the warning program and a feedback sign together produced an even greater reduction in speeding than either alone.

Effects of a Driver Enforcement Program on Yielding to Pedestrians

“…Third, the use of warnings allowed police to contact up to 20 times as many noncompliant motorists. Data show that the use of warnings greatly increases the effectiveness of enforcement (Van Houten & Nau, 1983), and a high frequency of stops ensures not only that many people directly make contact with the punishment contingency but also that many drivers witness these stops. It is interesting to note that after a few taxi drivers were cited for failing to yield during the first couple of days of the program, taxi drivers began to yield reliably.…”

“…One way to modify driver behavior is through enforcement programs. Van Houten and Nau (1983) compared the effects of an enforcement program that issued citations with one that issued primarily written and verbal warnings on speeding on urban streets. The results indicated that the effects of a 1-week enforcement program, which relied on citations alone, persisted only while the program was in effect, but that the effects of the warning program persisted for up to a year.…”

Effects of Environmental Design and Police Enforcement on Violations of a Handicapped Parking Ordinance

“…Although few drivers directly experienced the aversive consequence of a fine, many more may have seen police cars patrolling handicapped parking sites and ticketing violators. Van Houten and Nau (1983) and Van Houten et al (1985) indicated that the effectiveness ofpolice enforcement procedures may be a function of the density and visibility of punishment.…”

“…Issues have included littering (Geller, Winett, & Everett, 1982), trash packaging (Stokes & Fawcett, 1977), city crime (Schnelle, Kirchner, Casey, Uselton, & McNees, 1977), and speeding (Van Houten & Nau, 1983;Van Houten et al, 1985).…”

The Failure of Feedback on Alcohol Impairment to Reduce Impaired Driving

“…Feedback has been shown to be effective in reducing the incidence of speeding (Van Houten & Nau, 1983) and to increase yielding to pedestrians (Van Houten, Malenfant, & Rolider, 1985). Geller and his associates have suggested that providing feedback on alcohol impairment might be similarly effective in reducing the incidence ofimpaired driving (Geller, Altomari, & Russ, 1984;Geller & Lehman, 1988; Russ, 1986).…”