Impact of Monetary Penalty Driver Feedback on Work Zone Speed

Nationally, one work zone fatality occurs every 10 hours (about 2.3 a day) and one injury every 13 minutes (110 a day). Speed limit compliance in and around work zones is of concern to transportation agencies because of the correlation of excessive speeds as a primary causation factor for work zone crashes. Potentially up to 25% of fatal crashes in work zones involved high speeds.

Research was conducted using a changeable message sign with radar (CMSR) at one work zone location on a four-lane, divided highway in Arizona. The CMSR provided feedback to drivers about the amount of their potential traffic fine, which was triggered by the radar captured speed as their vehicles approached the CMSR. This type of feedback has had only limited study according to the authors’ literature search. The CMSR alternated a speed feedback message (YOUR SPEED XX MPH) with the message “POSSIBLE FINE $XXX,” wherein the dollar amount varied depending on the speed of the vehicle. As the vehicle slowed (or accelerated) the sign message changed to reflect their new speed and any resulting change in the amount of fine.

The findings indicate that coupling the speeding fine feedback with alternating vehicle speed provided an important observed performance in reducing speeds in the tested work zone. Reductions in mean speeds was modest, approximately 4 mph. However, the impact on excessive speeders was significant. The number of speeders traveling at or greater than 5 and 10 mph above the speed limit, were both reduced by one fourth. At the extreme speeds of 15, 20, and 25 mph over the speed limit, the number of speeding vehicles was reduced in each case by half.