This report presents the implementation and evaluation of four techniques for improving the effectiveness of speed zoning in construction areas on multi-lane freeways. The techniques are (a) the flagging procedure of the "Manual on Uniform Traffic Control Devices" (MUTCD), (b) the use of the MUTCD flagging procedure as well as motioning motorists to slow and pointing at a nearby speed limit sign with the free hand of the flagger, (c) a marked police car with cruiser lights and radar active, and (d) a uniformed police officer standing to control traffic. Each of the techniques were applied continuously on six-lane freeways for a period of 10-15 days. The results of the analysis indicate that all four techniques can derive significant reduction in traffic speed through highway construction zones. The flagging methods were effective in construction areas where one lane remained open to traffic. The law enforcement methods demonstrated a stronger speed reduction capability, particularly when the lane closures result in two or more lanes open. The construction projects used for the field data collection required speed reduction from the regulatory 55 mph to an advisory 45 mph. Although the law enforcement techniques were determined to be effective, their implementation requires a high degree of administrative coordination and cooperation involving police departments, highway officials and construction contractors. A User Guide on speed control in work zones is provided in Appendix B. (Author/publisher)
Samenvatting