Office of Operations
photos of traffic merging onto congested highway, congestion in snowstorm, variable message sign, cargo, variable speed limit sign in a work zone, and a freeway at night
21st Century Operations Using 21st Century Technologies

Traffic Bottlenecks


Case Studies

  • Arkansas - In 2009, Metroplan MPO (Little Rock region) conducted a public survey of localized congestion problems.
  • Austin, Texas - In 2009, Texas Department of Transportation completed a restriping of two lanes to "reclaim" a third lane.
  • City of Arvada, Colorado - A grade-separation project to eliminate recurring problems caused by a railroad crossing.
  • Danbury, Connecticut - Restriping the I-84 / Route 7 split saved Connecticut Department of Transportation from having to rebuild the whole interchange.
  • Madison, Wisconsin - Ramp meters were used to correct delays and crashes at five ramps along Highway 12.
  • Manchester, New Hampshire - Improvements to a congested exit ramp is expedited as part of long-term, phased construction.
  • Minneapolis-St. Paul, Minnesota - Results of a 2001 study to determine effectiveness of ramp meters.
  • Pittsburgh, Pennsylvania - Converted shoulder-into-acceleration lane at former chokepoint at top of ramp entrance.
  • Renton, Washington - Use the shoulder to maintain lane congruency and eliminate a lane drop chokepoint.
  • Saginaw County, Michigan - Replace tight diamond ramp intersections with roundabouts to combat insufficient signalized intersections.
  • Statewide "Moving Washington" Program - Description of Washington State's 3-tiered "Moving Washington" congestion relief plan.

State DOTs Bottleneck Reduction Processes

  • Arkansas, 2009, "Operation Bottleneck" Campaign - In 2009 the metropolitan planning organization "MetroPlan" (Little Rock region), in cooperation with the local media, undertook a short summer campaign via the internet, public meetings, and newspaper-based surveys, to solicit public input and comments through "Operation Bottleneck". In roughly one month's time, over 3,000 responses were received! Many responses validated already-planned projects. In some cases, immediate action was taken, such as removing or cutting back foliage to improve sight distances, attending to missing or damaged signs, or tweaking signals. In the short term, local governments used the information to consider new or additional traffic signage and signals, enhance signal coordination, support minor intersection improvements, or improve access-conflict (i.e., access management) situations as opportunities presented themselves.

    For the longer term, staff aggregated, and then disseminated the information to the locally responsible agencies. In some cases, regionally cooperative tasks will be undertaken (e.g., a consultant was tasked with reviewing more-complex traffic signal operations; corridor studies and/or spot-specific projects that will be realized, etc.) in direct response to the most accessible complaints. In other cases, Operation Bottleneck will influence regional-level decisions on major widenings and other transportation investments in the longer-term future.

    Operation Bottleneck makes government actions more directly responsible to citizens by providing thousands of people a chance to let their voices be heard. Public comment is invaluable in validating concerns and providing an outlet for the public to be heard. Action items confirm to the public that the agency is listening and can provide a response.
  • California DOT ("Caltrans") 2007 Bottleneck Reduction Process (HTML, PDF 34 KB)
  • Minnesota DOT 2007 Bottleneck Reduction Process (HTML, PDF 246KB) - In 2007 the Minnesota Department of Transportation developed a process to identify, rank, and execute low-cost congestion relief projects.
  • Ohio DOT Bottleneck Reduction Process (HTML, PDF 15KB) - In 2002 the Ohio Department of Transportation (ODOT) added a congestion index ranking to their "Highway Safety Program" listing of state hot spots. Now, congestion-identified locations have a "voice" in competing with safety-identified locations for priority attention.

Other Resources

  • An Agency Guide on How to Establish Localized Congestion Mitigation Programs (HTML, PDF 713KB) (Publication Number: FHWa-HOP-11-009)
  • An Agency Guide on Overcoming Unique Challenges to Localized Congestion Reduction Projects (HTML, PDF 6.3MB) (Publication Number: FHWA-HOP-11-034)
  • Bottleneck Impact Matrix (HTML, PDF One Pager 89KB) - A table displaying the differences between recurring and nonrecurring.
  • Do Bottleneck Improvements Really Reduce Congestion? (Texas Transportation Institute, 2002) (PDF 1.6MB)
  • Ramp Meters (HTML, PDF 322KB) - A short history and discussion of their use, including their use in small, medium, and large SMAs, as of December 2012.
  • Recurring Traffic Bottlenecks: A Primer Focus on Low-Cost Operational Improvements (Version 3) (HTML, PDF 2MB) (Publication Number: FHWa-HOP-12-012)
  • Traffic Analysis Toolbox Volume X: Localized Bottleneck Congestion Analysis Focusing on What Analysis Tools Are Available, Necessary and Productive for Localized Congestion Remediation (HTML, PDF 638KB) (Publication Number: FHWA-HOP-09-042) - This document will provide guidance that specifies the choice of analysis tools and inputs necessary to analyze localized problem areas.

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