Improving Work Zone Safety for Freight Vehicles: Effective Design Patterns for Vehicle Mounted Attenuators

This report presents a study of driver perceptions using a driving simulator carried out on the effectiveness of four markings which vary in striping patterns and color combinations used at the rear of vehicle mounted attenuators (VMAs) in work zones during daytime, dusk and nighttime. One hundred and twenty participants from different age groups took part in the evaluation of VMA markings by driving through virtual highway work zones. During this experiment, driver reaction to VMA markings was determined based on their lane change distance (LCD). Additionally, the drivers were surveyed using a detailed subjective survey. Analysis of variance (ANOVA) was performed to determine the significant variables affecting the LCD. For each time of day, a pair wise least-square means test was conducted to calculate the difference in LCD between the markings. A Kolmogorov-Smirnov test was carried out to evaluate the significance of differences between the LCD frequency distributions of the markings. For the subjective evaluation, the markings were ranked by participants indicating their preferences using four different criteria for each time of day. The participants were also surveyed on the features of the individual markings and for the most preferred marking. The results of the objective and subjective evaluations indicated that, overall, the red and white checkerboard pattern was most effective.