The objectives of this study were to evaluate the effectiveness of work zone business driveway delineation alternatives. To accomplish this, the researchers first conducted a literature review to identify driveway delineation alternatives used or considered by other transportation agencies. Low-profile longitudinal channelizing devices (LCDs) were found to have good potential to address various concerns with current work zone business driveway delineation practices. The researchers conducted a closed-course study at the Texas A&M University Riverside Campus testing facility in order to identify the best LCD configurations for further evaluation during the field studies. Based upon those results, the researchers performed field studies in Florida work zones to evaluate LCDs and compare them to the standard drum treatment used in Florida. During the field studies, the researchers collected video data of turning movements to conduct an erratic maneuvers study. They also recorded speed profiles, which were used to compare speeds and speed changes along the driveway approaches. In addition, a survey of driveway users was administered in order to garner opinions about the driveway treatments. Overall, the researchers found no negative operational impacts of delineating business driveways with low-profile LCDs in work zones. The erratic manoeuvres study showed no hard braking or swerving at any of the driveway treatments. However, two work zone intrusions occurred while the drum treatment was deployed. The speed profile study results indicated no differences in the speed reductions at either driveway treatment. However, a survey of users (including business owners, managers, employees, and customers who used the driveways) revealed that drivers had a preference for the LCDs over the drums. The researchers found no adverse traffic operational impacts as a result of using low-profile LCDs to delineate driveways in work zones; they also found a driver preference for the use of low-profile LCDs over drums to better convey driveway locations. While the researchers’ conclusions are based on a limited amount of data, the findings of this study are consistent with other recent research (Research Project 0-6781) sponsored by the Texas Department of Transportation. Based on these study results, researchers believe that low-profile (21 inches or less in height) LCDs can be an effective improvement to drums for driveway delineation in confined urban work zones where the speed limit is 45 mph or less. (Author/publisher)
Samenvatting