Evaluation of Work Zone Speed Reduction Measures (Report)

The Iowa Department of Transportation (DOT) has made improving work zone (WZ) safety a high priority. Managing vehicle speeds through work zones is perceived to be an important factor in achieving this goal. A number of speed reduction techniques are currently used by transportation agencies throughout the country to control speeds and reduce speed variation at work zones. The purpose of this project is to study these and other applicable work zone speed reduction strategies. Furthermore, this research explores transportation agencies’ policies regarding managing speeds in long-term, short-term, and moving work zones. This report consists of three chapters. The first chapter, “Literature Review,” examines the current speed reduction practices at work zones and provides a review of the relevant literature. The speed control strategies reviewed in this chapter range from posting regulatory and advisory speed limit (SL) signs to using the latest radar technologies to reduce speeds at work zones. The second chapter, “Technology Description,” includes a short write-up for each identified speed control technique. The write-up includes a description, the results of any field tests, the benefits, and the costs of the technology or technique. To learn more about other state policies regarding work zone speed reduction and management, the Center for Transportation Research and Education (CTRE) conducted a survey. The survey consists of six multipart questions. The third chapter, “Survey,” provides summaries of the response to each question. Copies of the survey and the cover letter are included in appendix A.