An Analysis of Public Posting in Reducing Speeding Behavior on an Urban Highway

Abstract

The effects of public posting on speeding behavior on an urban highway were assessed using a reversal design. During baseline the percentage of drivers speeding was measured with a concealed radar unit. During the daily posting condition a highway sign was installed which provided feedback on the percentage of drivers not speeding yesterday and the best record to date. This sign was then covered and reintroduced. Results indicated that the sign was effective in reducing speeding behavior. Furthermore, the effects were most pronounced in reducing the speeds of the faster drivers. Next, daily and weekly postings were compared with the sign alone without numerical feedback: results revealed that the weekly posting condition was as effective as the daily posting condition, but that the sign had no influence when numbers were not posted. Finally, the weekly posting procedure remained effective during a 6-month follow-up condition.DESCRIPTORS: public posting, speeding behavior, driving speed, feedback, highways, police procedures, driving behavior Although the automobile is certainly a useful tool, its use is also associated with societal costs such as accidents and resulting casualties. One factor that has been associated with accidents is deviation from prudent driving speeds. Data obtained from many American states (Cirillo, 1968) show that as vehicle speed varies from the mean traffic speed, the chance of an accident increases.One method of managing excessive speeds and thereby decreasing accidents is the posting of speed limits.

Feedback Interventions and Driving Speed: A Parametric and Comparative Analysis

“…In previous research the feedback sign has always been used at the beginning of residential or business sections at a location where the posted speed limit has been reduced (Van Houten, Nau, & Marini, 1980;Van Houten & Nau, 1981). These studies have demonstrated that posted feedback can be effective in increasing compliance with a change in speed limit.…”

“…Speeds of vehicles were measured using a MuniQuip DRS 3 Radar manufactured by Tribar Industries, Weston, Ontario, Canada, used in the same manner as described by Van Houten et al (1980). Prior to beginning each session the calibration of the unit was checked by switching on the unit and holding a vibrating tuning fork in front of the radar antenna.…”

“…One technique that decreases vehicle speed is posting of the percentage of drivers not speeding, along with the best record to date, on a highway sign (Van Houten, Nau, & Marini, 1980;Van Houten & Nau, 1981). This technique reduced serious speeding (85th percentile speeding) by over 50%.…”

“…Moreover, the effects of the presence of the feedback sign in the original study have persisted for approximately 4 years at the time of this writing. Van Houten et al (1980) and Van Houten and Nau (1981) posted the percentage of drivers traveling less than 16 and 14 km/hr over the speed limit, respectively, as not speeding. These criteria for speeding were chosen rather than the posted limit because police authorities did not consider vehicles traveling under these speeds to be significant threats to safety.…”

“…One purpose of the second experiment was to determine how far the effects of the feedback sign persisted along a stretch of highway. Since all previous studies have been conducted along urban undivided highways with residential speed limits (Van Houten et al, 1980;Van Houten & Nau, 1981), a second purpose of this study was to determine if the feedback sign would be effective on a limited access divided highway with a high speed limit (100 km/hr).…”