Across Texas, more and more road work is being done at night. However, very few data has been collected to quantify whether traffic safety is improved or worsened by shifting work activities to night hours. Crash rates on roadways are normally higher at night because visibility is reduced and a greater proportion of drivers are impaired or drowsy. On the other hand, traffic volumes are much lower at night, which reduces the overall level of traffic exposure to work activities. Working at night also reduces the frequency and extent of traffic queues that are created, a condition that correlates with increased crash risk. In this project, researchers quantified and characterized the level of traffic safety risks associated with night work activities in Texas and evaluated the likely effectiveness of several countermeasures that have been proposed to further improve night work zone safety.