Assessing the Safety Impacts of Active Night Work Zones in Texas

Researchers present a summary of the extent and type of nighttime work zone activity that currently occurs in Texas; an analysis of Department of Public Safety (DPS) crash data to assess the ramifications of night work on crash experiences; and an assessment of differences in operational characteristics of traffic at nighttime and daytime work zones. Researchers found that the amount of active night work occurring in the districts correlates well with the overall traffic demands (expressed as total vehicle-miles-traveled per lane-mile of responsibility) in the district. Once district-wide demands reach 2000 vehicle-miles-traveled per lane-mile, active night work begins to take on a greater role in the district. However, researchers did not find a significantly greater propensity for night work zone crashes or for more severe nighttime crashes in those districts with significant amounts of night work. Researchers did find that crashes on nights with work activity were slightly more frequent, in general, than those during nights of inactivity or during daytime periods. Projects that were believed to have experienced significant levels of traffic queuing at night when lane closures were instituted appeared to experience the greatest increase in crashes. Additional analysis and findings are also presented in the report.