Office of Operations
21st Century Operations Using 21st Century Technologies

Recurring Traffic Bottlenecks: A Primer
Focus on Low-Cost Operational Improvements

Contact Information: Neil Spiller at
Traffic Bottlenecks Web Site

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U.S. Department of Transportation
Federal Highway Administration
Office of Operations (HOP)
1200 New Jersey Avenue, SE
Washington, DC 20590

Publication Number: FHWA-HOP-12-012

U.S. Department of Transportation, Federal Highway Administration

April 2012

Table of Contents



When Did "Plan on Being Delayed" Become Part of Our Everyday Lexicon?

Traffic, Like Weather, is an Ever-Evolving "Front"

"Bottlenecks" and not "Insufficient Facilities" is Increasingly the Problem

Understanding Bottlenecks

What Exactly is a "Traffic Bottleneck"?

"Good News" and "Bad News" About Fixing Bottlenecks

Understanding Merging at Recurring Bottlenecks

Merge Principles

What is FHWA Doing to Promote Congestion Relief and Bottleneck Mitigation?

Recurring Congestion Program Strategies

Nonrecurring Congestion Program Strategies

The Localized Bottleneck Reduction Program – Focus on Recurring Congestion

Benefits of Localized Bottleneck Improvements

Getting Started: How to Structure a Localized Bottleneck Reduction Program

What is Stopping Us From Fixing Bottlenecks?

Overcoming Challenges to Implementing LBR Projects

Options for Structuring a Bottleneck Improvement Program

Potential Issues with LBR Bottleneck Treatments

Identifying and Assessing Bottlenecks

Where are the Bottlenecks and How Severe Are They?

Localized Bottleneck Reduction Strategies

Types of LBR Treatments

Innovative Intersection and Interchange Design Treatments

Success Stories: How Agencies Are Deploying LBR Treatments and Developing Programs

Case Studies

Successful LBR Program Development

Want More Information?


FHWA Matrix of Bottleneck Terms


Exhibit 1. Common Locations for Localized Bottlenecks

Exhibit 2. The Worst Physical Bottlenecks in the United States (2010)

Exhibit 3. Typical Section of MN I-35W Northbound Priced Dynamic Shoulder Lane (PDSL)

Exhibit 4. Examples of How Agencies Have Addressed Localized Bottleneck Issues

Exhibit 5. MnDOT Project Screening Process

Exhibit 6. Using Freeway Detector for Bottleneck Analysis

Exhibit 7. Using Vehicle Probe Data for Bottleneck Analysis

Exhibit 8. Vehicular Movements at a Continuous Flow Intersection

Exhibit 9. Crossover Movement in a DCD Interchange

Exhibit 10. Successful LBR Treatments – Austin, Texas

Exhibit 11. Successful LBR Treatments – Arvada, Colorado

Exhibit 12. Successful LBR Treatments – Saginaw, Michigan

Exhibit 13. Successful LBR Treatments – Metroplan MPO/Little Rock

Exhibit 14. Successful LBR Treatments – Pittsburgh, Pennsylvania

Exhibit 15. Success Spawns Success

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