Strategies to Reduce Truck Mounted Attenuator Crashes

Virginia has seen an annual increase in truck mounted attenuator (TMA) crashes since 2015. These have primarily been struck-from-behind crashes during mobile operations. The objective of this project was to identify the most promising methods that could reduce the occurrence and severity of TMA crashes in construction and maintenance work zones, including both stationary and mobile operations. Specifically, this study examined the impact of various retroreflective panel configurations on the speed and lane selection of traffic in the area behind the TMA truck. A literature review was performed identifying aspects of a TMA and TMA truck that could be modified to reduce crashes. Of these aspects, marking patterns and colors were selected for field testing. A TMA truck was parked on the right shoulder of a public highway and data was collected regarding the lane selection and speed of traffic that traveled past the truck. Ten treatments were tested: two different patterns, four different color schemes, and two panel configurations. Effectiveness was measured by the left lane occupancy rate and mean traffic speed for each treatment. A higher left lane occupancy and lower average speed were considered desirable. Results showed that a
checkered pattern was more effective than chevrons, that green and black was the best performing color scheme, and that the addition of an upper panel increased effectiveness. A yellow and orange color scheme was found to be the worst performer. However, due to limitations of the study – specifically that testing was only conducted in daylight at one location – no recommendations for changes to TMA markings are being made. The results of this study should be used to inform further research which expands on this effort.