01138083

Component

http://www.trb.org/Publications/Blurbs/161920.aspx

Variable speed limit (VSL) signs are used across the country in conjunction with intelligent transportation systems to lower posted speed limits in areas affected by conditions such as congestion, construction, accidents, fog, snow, and ice. VSL signs allow operators to adjust the posted speed limit without changing the physical sign. As technology advances, the ease of using VSL signs is also increasing since speeds can now be changed at preset times via e-mail or telephone, or manually at the site. The Utah Department of Transportation desired to evaluate the effectiveness of this technology on driver behavior before using it widely in work zones on state highways. The focus of this research is driver response to VSL signs. A six-mi-long test site with a long-distance work zone on I-80 north of Wanship, Utah, was used to test drivers’ responses to VSL signs. Five speed detectors and two VSL signs were placed in this zone and vehicle speeds were monitored for about 3 months. The speed data analyses showed that driver response was positive. Though the average speeds between static speed limit signs and VSL signs were not statistically different at a 95% confidence level, variation in speeds was reduced in general, especially at the first speed detector location downstream of the first VSL sign. Providing drivers with speed restrictions that reflect actual conditions builds trust in the posted speed. Long-term use of VSL signs is recommended for evaluating their long-term effect on driver compliance to reduced work zone speed limits.

01138080

MMC09-008

English

pp 159-174

2009-7

Transportation Research Circular

12th AASHTO-TRB Maintenance Management Conference

Web

Figures (8) ; Photos (1) ; References (7) ; Tables (3)

Compliance; Speed control; Speed limits; Variable message signs; Variable speed limits; Work zone traffic control

Utah Department of Transportation

Wanship (Utah)

Highways; Maintenance and Preservation; Operations and Traffic Management; Pavements; I60: Maintenance; I73: Traffic Control

TRIS, TRB

Aug 4 2009 3:08PM

• A Wireless Sensor for Monitoring Chloride Ingress in Concrete
• Asset Management Plan for the Ambassador Bridge
• Concrete Pavement Preservation and Rehabilitation to Meet Sustainability Demands
• Cost–Benefit Analysis of the Pooled-Fund Maintenance Decision Support System: Case Studies
• Development of a Comprehensive Framework for the Efficiency Measurement of Road Maintenance Strategies Using Data Envelopment Analysis
• Implementation of a Pavement Preservation Program in Illinois
• Integrating Maintenance Management Systems with Maintenance Decision Support Systems
• Long-Term Performance of Failed Flexible Pavements Stabilized with Cement
• Management of Environmental Features and Assets
• Maximizing Resource Use to Meet the Maintenance Management Challenge: As Demonstrated by Traffic Signal Maintenance Management in the City of Norfolk, Virginia
• North Carolina Department of Transportation’s Performance-Based Contracting Experience in Charlotte
• Performance-Based Contracting—Yes or No: An In-Depth Analysis
• Solving Maintenance Issues in Design and Construction
• Transportation Supervisor Workforce Development for the North Carolina Department of Transportation
• Use and Cost–Benefit of Weather Information in Winter Maintenance
• Use of Monte Carlo Simulation to Evaluate the Kansas Department of Transportation's Maintenance Quality Assurance Program
• Use of PDAs to Capture Field Data for Input in North Carolina’s Maintenance Management System