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原文传递 Evaluation of Traffic Control Devices: Third-Year Activities.

题名：	Evaluation of Traffic Control Devices: Third-Year Activities.
作者：	HAWKINS, H. G.; SNEED, M. A.; WILLIAMS, C. L.
关键词：	PERFORMANCE EVALUATION; TRAFFIC CONTROL DEVICES
摘要：	This project was established to provide a means of conducting limited scope evaluations of numerous traffic control device issues. During the third year of the project, researchers completed assessments of three issues: a red border Speed Limit sign, sign and marking design for super high-speed roadways, and a comparison of retroreflectivity measurements made with portable and mobile retroreflectometers. The evaluation of the red border Speed Limit sign indicates that the red border treatment has a beneficial impact on reducing speeds at locations where the speed limit decreases. The researchers recommend using the red border to improve the conspicuity of Speed Limit signs at these locations. On super high-speed roadways, the researchers recommend that the legend on guide signs be a minimum of 22 inches and that an additional guide sign installation be provided in advance of the exit. Furthermore, sign sheeting for overhead signs on super high-speed roads should be limited to sheeting types that will provide adequate luminance. Pavement markings on these highways should be at least 6 inches wide. The researchers found that portable and mobile measurements are consistent with one another if both retroreflectometers are properly calibrated and operated. As part of the third-year activities, the researchers also evaluated lateral spacing for edge line rumble strips on two-lane highways, revised a set of guidelines for conducting a traffic signal warrant analysis, and are developing a handbook that will provide guidance on assessing and addressing the work zone impacts of significant projects.
报告类型：	科技报告