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Technical Report Documentation Page
1. Report No. FHWA-HOP-07-130 |
2. Government Accession No. |
3. Recipient’s Catalog No. |
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4. Title and Subtitle Traffic Bottlenecks: A Primer |
5. Report Date July 2007 |
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| 6. Performing Organization Code | ||||||
7. Author(s) Richard A. Margiotta, CSI. / Neil C. Spiller, FHWA / John Halkias, FHWA |
8. Performing Organization Report No. |
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9. Performing Organization Name and Address Cambridge Systematics, Inc. |
10. Work Unit No. |
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11. Contract or Grant No. |
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12. Sponsoring Agency Name and Address U.S. Department of Transportation |
13. Type of Report and Period Covered |
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14. Sponsoring Agency Code HOTM |
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15. Supplementary Notes Contact: Neil C. Spiller, FHWA, HOTM-1, 202-366-2188 |
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16. Abstract While many of the nation's bottlenecks can best be addressed through costly major construction projects (i.e., "mega projects") or costly transportation alternative solutions (e.g., high occupancy vehicle or toll lanes, dynamic pricing, investments in transit alternatives, etc.) there is significant opportunity for the application of operational and low-cost infrastructure solutions to bring about relief either in the short term or as an alternative to big budget solutions. This primer is one of the signature products of the Localized Bottleneck Reduction (LBR) program, which is administered out of the FHWA Office of Transportation Management. The LBR program is focused on recurring congestion chokepoints (as opposed to nonrecurring congestion problems) and the operational influences that cause them. Operational influences are the highway junction and decision points (e.g., lane drops, weaves, on- and off ramps, signals, intersections, merges, tollbooths, width-restricted underpasses, etc.) that can become overwhelmed by vehicle volume on a recurring basis. The facility itself, at that point, and at predictable recurring times of day, is the capacity limiting determinant. Upstream and downstream of these points, the facility seems capable of handling the volume, and traffic flow tends towards free flow rates. Widening, lengthening, retiming, metering, or bypassing these troublesome locations with intent to generally unclog them can often be done with lower cost, lesser intensive means than traditionally waiting for a complete facility redesign, an out-year project, or a new complementary facility, etc. While pricing, driver incentives, and systemic solutions have their place, so too exists the option to take a fresh look at an old problem and see if there isn't a quicker, less intrusive fix that can be made. In much the same way that a transportation agency might have an annual safety-spot improvement program to address localized, high-crash problems areas, the agency should also have an annual congestion-relief improvement program to address localized, recurring chokepoints. If the ultimate fix must be a complete overhaul (e.g., high cost replacement, upgrade, or defacto new facility) then so be it; but an agency shouldn't limit itself to only "building our way out of congestion." |
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17. Key Words bottleneck, chokepoint, recurring congestion, low cost improvements, operational deficiencies, operational influences, lane drops, weaves, merges, metering |
18. Distribution Statement No restrictions. This document is available to the public through the National Technical Information Service, Springfield, VA 22161. |
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19. Security Classif. (of this report) Unclassified |
20. Security Classif. Unclassified |
21. No of Pages 24 |
22. Price na |
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Form DOT F 1700.7 (8-72) Reproduction of completed pages authorized
