Effectiveness of Temporary Traffic Control Measures in Highway Work Zones

In the United States, hundreds of people lose their lives each year and many more are injured due to vehicle crashes in the work zones. Over the years, temporary traffic control (TCC) measures have been developed and deployed in work zones. To continuously improve the safety, there is a need to identify the traffic control deficiencies in work zones by evaluating the effectiveness of existing TTC measures based on the real crash cases. In this study, researchers evaluated the effectiveness of several commonly used TTC methods using logistic regression techniques and various significance test methods including likelihood ratio test, score test, and Wald test. These TTC methods included flagger/officer, stop sign/signal, flasher, no passing zone control, and pavement center/edge lines. A total of 655 severe crashes in Kansas
highway work zones between January 2003 and December 2004 were used for the evaluation, which included 29 fatal crashes and 626 injury crashes. Results indicated that flagger, flasher, and pavement center/edge lines were effective in reducing the probability of causing fatalities when severe crashes occurred. In addition, using these devices could prevent some common human errors, such as ‘‘disregarded traffic control,” ‘‘inattentive driving,” ‘‘followed too closely,” and ‘‘exceeded speed limit or too fast for condition,” from causing severe crashes.