U.S. Department of Transportation
Federal Highway Administration
1200 New Jersey Avenue, SE
Washington, DC 20590
202-366-4000
1. Report No. FHWA-SA-11-22 |
2. Government Accession No. |
3. Recipient's Catalog No. |
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4. Title and Subtitle Procedures for Setting Advisory Speeds on Curves |
5. Report Date June 2011 |
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6. Performing Organization Code |
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7. Author(s) R. Milstead, X. Qin, B. Katz, J. Bonneson, M. Pratt, J. Miles, and P. Carlson |
8. Performing Organization Report No. |
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9. Performing Organization Name and Address Brudis & Associates, Inc. |
10. Work Unit No. (TRAIS) |
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11. Contract or Grant No. |
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12. Sponsoring Agency Name and Address US Department of Transportation - Federal Highway Administration |
13. Type of Report and Period Covered October 2009 – June 2011 |
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14. Sponsoring Agency Code |
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15. Supplementary Notes Project performed for the Federal Highway Administration |
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16. Abstract Horizontal curves are a necessary component of the highway alignment; however, they tend to be associated with a disproportionate number of severe crashes. Warning signs are intended to improve curve safety by alerting the driver to a change in geometry that may not be apparent or expected. However, several research projects conducted in the last 20 years have consistently shown that drivers are not responding to curve warning signs or complying with the Advisory Speed plaque. It is estimated that half of all speeding related roadway departure crashes occur on curves. One of the reasons that curves are overrepresented in speeding related fatalities is due, in part, to advisory speeds that are not consistent, and therefore, not credible. A project by Texas Transportation Institute (TTI), Texas Research Project
0-5439 "Identifying and Testing Effective Advisory Speed Setting
Procedures", exemplifies how current procedures for setting advisory
speed on curves are not reliable, and has developed new criteria and a
new procedure that are more consistent with driver expectation. The new
procedure involves the use of an Excel spreadsheet and a handbook for
applying the new criteria. |
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17. Key Words Traffic Control Devices, Warning Signs, Speed Signs, Highway Curves, Speed Measurement, Trucks, Traffic Speed |
18. Distribution Statement No restrictions. |
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19. Security Classification (of this report) Unclassified |
20. Security Classification (of this page) Unclassified |
21. No of Pages 42 |
22. Price N/A |
Form DOT F 1700.7 (8-72)
Reproduction of completed page authorized.