Evaluation of Work Zone Speed Limit Signs with Strobe Lights

Evaluation of Work Zone Speed Limit Signs with Strobe Lights

Author: R. F. Benekohal

Publisher:

Published: 1992

Total Pages: 98

ISBN-13:

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The construction zone speed limit sign used in Illinois consists of a regulatory 45 mph speed limit sign augmented with two small strobe lights and two orange colored plates. When the lights are flashing the speed limit is 45 mph. This report contains the findings from evaluation of the effectiveness of the flashing lights in reducing speeds in a rural interstate construction zone. The speed reduction effects on cars and trucks were determined at two locations within the work zone. The results indicated that the average speed of cars was reduced by 1.9-7.1 mph and that of trucks by 1.3-6.0 mph when the strobe lights were flashing. In general, the speed reduction effects were more pronounced on the cars than on the trucks, and at a location past the work space than before it. The reductions at the location past the work space were 2-3 times more than the reductions at the location before the work space. Cars reduced their speeds, on the average, by 1.9 to 4.9 mph before and by 5.9 to 7.1 mph after the work space. Similarly, the speed reduction for trucks was 1.3-2.9 mph before and 3.3-6.0 after the work space. In general, the percentages of vehicles with excessive speeds in the work zone decreased when the lights were flashing.


Evaluation of Work Zone Speed Reduction Measures

Evaluation of Work Zone Speed Reduction Measures

Author: T. H. Maze

Publisher:

Published: 2000

Total Pages: 146

ISBN-13:

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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, a 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 signs to using the latest radar technologies to reduce speeds at work zones. The second chapter 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 conducted a survey. The survey consists of six multipart questions. The third chapter provides summaries of the response to each question.


Speed Reduction Methods and Studies in Work Zones

Speed Reduction Methods and Studies in Work Zones

Author: R. F. Benekohal

Publisher:

Published: 1992

Total Pages: 82

ISBN-13:

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The objectives of this project were to determine the effectiveness of speed control methods and study traffic behavior in construction zones. This report provides a brief introduction and summary of findings from the following reports which were prepared as part of this study: (1) Evaluation and Summary of Studies in Speed Control Methods in Work Zones. (2) Evaluation of a Radar-Activated Horn System for Speed Control in Highway Maintenance Operations. (3) Survey of Driver's Opinion about Work Zone Traffic Control on a Rural Highway. (4) Speed Reduction Effects of Drone Radar in Rural Interstate Work Zones. (5) Speed Reduction Effects of Changeable Message Signs in a Construction Zone. (6) Effects of Police Presence on Speed in a Highway Work Zone: Circulating Marked Police Car Experiment. (7) Evaluation of Work Zone Speed Limit Signs with Strobe Lights. (8) Speed Reduction Profiles of Vehicles in a Highway Construction zone. Data only for those vehicles in free flow traffic are used for speed reduction evaluation. A vehicle was considered to be in free flow traffic when its time headway was greater than 5 seconds.


Roadside Design Guide

Roadside Design Guide

Author: American Association of State Highway and Transportation Officials. Task Force for Roadside Safety

Publisher:

Published: 1989

Total Pages: 560

ISBN-13:

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Development and Evaluation of an Active Warning Device for School Bus Loading and Unloading Points in Areas of Limited Visibility

Development and Evaluation of an Active Warning Device for School Bus Loading and Unloading Points in Areas of Limited Visibility

Author:

Publisher:

Published: 2005

Total Pages: 112

ISBN-13:

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The primary objectives of this research project were: (1) to develop an active advance warning device (AAWD) comprised of an actuated flashing beacon supplement to a conventional SCHOOL BUS STOP AHEAD sign (S3-1) and (2) to evaluate its effect on driver performance and safety through school bus loading and unloading zones. Secondary objectives were to summarize system components and costs, develop an activation strategy, review the liability risk, review national experience related to safety, and provide guidance regarding specifications and use in Texas. With respect to safety, 37 of 46 studies reported a positive effect resulting from AAWDs. Findings from field studies conducted in Texas also suggest favorable results with confirmed reductions in vehicle approach speeds when the flashing beacon was activated. Costs for the final AAWD are estimated to be 2,000 dollars for the S3-1 sign and flashing beacons and 2,600 dollars for the flashing beacon activation system, not including sign installation or ongoing maintenance and operations costs. A review of published literature and historic case law suggests minimal additional liability risk above what is already experienced by transportation departments. Unique areas of risk relate to "jurisdictional responsibility" for establishing, operating, and maintaining school bus loading and unloading zones and the hazard expectation tied to the flashing beacon activation (i.e., motorists may not exercise the same degree of caution when the bus is not present and the beacons are not flashing despite children being present at the bus stop). Given the favorable safety impacts, the low system cost, and the minimal additional liability risk incurred, the AA WD is recommended for further implementation.


Human Factors Guidelines for Road Systems

Human Factors Guidelines for Road Systems

Author: John L. Campbell

Publisher: Transportation Research Board National Research

Published: 2012

Total Pages: 348

ISBN-13: 9780309258166

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"This report completes and updates the first edition of NCHRP Report 600: Human Factors Guidelines for Road Systems (HFG), which was published previously in three collections. The HFG contains guidelines that provide human factors principles and findings for consideration by, and is a resource document for, highway designers, traffic engineers, and other safety practitioners."--Foreword.