There are times when the traffic lanes through a work zone must be kept clear for activities such as placing overhead beams, erecting overhead signs, and installing power lines, and other temporary roadway work activities. As an alternative to a full road closure, a rolling slowdown can typically provide up to 30 minutes to complete such activities without bringing approaching traffic to a complete halt. Using data from recent rolling slowdowns and full closures carried on the Indiana interstate network and a simulation approach, this study compares rolling slowdowns to full closures from safety and mobility standpoints. The study suggests that while rolling slowdowns are more impactful in terms of travel times, they are a safer option than full closures as they often form a forward moving shockwave causing, lower hard braking rates, and consequently a lower probability of causing a crash.

Report Number



rolling slowdown, pacing operation, probe data, traffic simulation, traffic safety

SPR Number

4542 Volume 2

Performing Organization

Joint Transportation Research Program

Publisher Place

West Lafayette, IN

Date of this Version