Researchers
Mark Virkler
About the research
This study examined the effect of rumble strips on lane distributions, vehicle speeds, and vehicle conflicts at a long-term work zone in Missouri. The rumble strips were primarily intended to reduce the percentage of vehicles in the closed lane, traffic speeds, and speed variability. The data analysis examined the difference in the parameters before and after the devices were installed. The primary measures of effectiveness were lane distributions, speed mean, and speed variance; however, other parameters were also studied for significance in the evaluation of the traffic control devices. For the before and after studies, the analysis took into consideration the effects of time of day and class of vehicle.
The rumble strips were associated with improved lane distribution at the beginning of the lane drop during both the day and night. The mean, 85th percentile, and mean speeds of the fastest 15% of vehicles all showed improvement with the rumble strips in place. The only negative change in traffic flow characteristics associated with the rumble strips was a tendency for increased speed variance, exhibited in some of the observations through an increase in the standard deviation of speed and a decrease in the percentage of vehicles within the 10-mph pace.
The study also examined the ease of installation and removal and the durability of the rumble strips. Installation required approximately 3.5 hours for a two-person team, including temporary lane closures for both lanes, while removal required approximately 2.0 hours. In general, the rumble strips maintained their structural integrity under eight days of traffic, with about 14,600 vehicles per day, including 25.6% vehicles with three or more axles. The first, failed installation attempt indicated that installing the rumble strips on possibly damp pavement without the use of a 200-lb roller can result in nearly immediate failure. The second, successful installation indicated that the rumble strips can adhere well when applied to dry pavement with a 200-lb roller.
Finally, the study examined the safety of the rumble strips. No adverse effect on traffic safety was found.
Vendor: Advanced Traffic Markings