Impact of Temporary Portable Work Zone and Personal Lighting on Vehicle Speeds in Nighttime Highway Preservation Projects

Every year thousands of people are killed or injured in work zone crashes in the US due to excessive speed, distraction, inattentiveness, or low visibility. Many highway construction, maintenance, and pavement projects occur at night when the traffic volume is low, creating less congestion and delay to the traffic. During nighttime operations, however, ability of drivers to see workers is diminished. High speed roadways with low visibility make an unsafe and dangerous situation for both motorists and workers. In this paper the impact of additional temporary lighting on vehicle speed in highway work zones was investigated. In addition, the impact of wearing personal lighting equipment was also examined during paving operations. Two common types of lighting equipment, a light tower and a balloon light, were set up in work zones and a personal, wearable light was used during two paving projects on Oregon highways. Traffic speed and other vehicle and lighting data were collected on different nights when the lighting equipment was turned on and also when it was turned off. The research findings indicate that both additional temporary roadway lighting and personal lighting help to make workers more visible to motorists and equipment operators. Although a temporary light leads to slightly higher vehicle speeds, it makes the work zone and workers more visible for motorists and equipment operators. Statistical analysis revealed that there is no difference between mean vehicle speed with and without personal lights turned on. Personal, wearable lights are highly recommended for workers who are located away from large equipment and other light sources.