Evaluation of Traffic Controls for Highway Work Zones

The objective of this research was to evaluate the effectiveness of channelizing traffic control devices and to determine how these devices should be designed and used to guide drivers as they approach and proceed through a work zone. Research included device size, shape, reflectorization, internal illumination, and spacing for both day and night conditions; only stationary work zones were studied (i.e., major reconstruction type projects). This research was carried out in two phases-NCHRP Project 17-4, “Evaluation of Traffic Controls for Street and Highway Work Zones,” and NCHRP Project 17-4(2), “Evaluation of Traffic Cones and Tubes for Street and Highway Work Zones.” The effectiveness of barricades, panels, cones, and tubes was initially investigated in Project 17-4 through a series of tests including simulated conditions in a laboratory setting, controlled field tests using instrumented vehicles on closed highway sections, and observation of driver performance at actual construction sites. Because the traffic cones and tubes tested in the first phase displayed relatively poor characteristics under nighttime conditions, further study of these devices using improved reflectorization and internal lighting was conducted in the second phase, Project 17-4(2). The second phase consisted of controlled studies on closed highway sections. Both phases were conducted by Bio-Technology, Inc., and the combined findings are described in this report.