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21st Century Operations Using 21st Century Technologies
Table of Contents

Recurring Traffic Bottlenecks: A Primer
Focus on Low-Cost Operational Improvements (Fourth Edition)

Chapter 3. Dealing With Bottlenecks Programmatically

What is the Federal Highway Administration Doing to Mitigate Bottlenecks?

The Federal Highway Administration's (FHWA) Localized Bottleneck Reduction (LBR) program is entirely aimed at reducing localized, recurring congestion caused by bottlenecks. The LBR program promotes operational and low-cost bottleneck mitigation strategies to improve mobility at specific locations. Managed by the FHWA Office of Operations, the program serves to bring attention to the root causes, impacts, and potential solutions to traffic chokepoints that cause recurring congestion; ones that are wholly the result of operational influences. The goal of the program is to raise awareness of bottlenecks at the State level and promote low-cost, quick-to-implement geometric and operational improvements to address recurring chokepoints. The LBR program has pursued this goal through several activities, including:

  • This primer, which is in its fourth iteration and provides an overview of the wide range of operational and low-cost strategies available to reduce congestion at bottlenecks as well as guidance for agencies implementing LBR programs.
  • A compendium of State best practices in bottleneck identification, assessment, countermeasures, and evaluation—including how bottlenecks are treated in the annual planning and programming processes.
  • Version X of the Traffic Analysis Toolbox which focuses on what analysis tools are available, necessary, and productive for localized congestion remediation.
  • State-specific workshops for State and local agencies to learn and share information on localized bottleneck reduction strategies and how they can be incorporated into their respective planning processes. (Contact the Office of Operations if your agency is interested in hosting a no-cost to you workshop that looks into congestion and treatments.)

In concert with the LBR program, the FHWA promotes the mitigation of other types of congestion, in particular systemic, recurring congestion as well as nonrecurring congestion. Key strategies to reduce systemic, recurring congestion include tolling and pricing; public-private partnerships; real-time traveler information; corridor traffic management; arterial management and traffic signal timing; and active traffic management. Key strategies to reduce nonrecurring congestion include transportation systems management and operations (TSMO); traffic incident management (TIM); work zone management; road weather management; and the Highways for LIFE program. Strategies to manage all types of congestion are critical to enhancing the mobility and reliability of the nation's highway system—as is knowing when and where to apply each strategy.

Benefits of Localized Bottleneck Reduction Strategies

The LBR program focuses on operationally influenced bottlenecks—small, localized "hot spots" where the design of the roadway itself becomes the constricting factor in processing traffic demand, resulting in recurring delays of generally predictable times and durations. Megaprojects required to resolve major bottleneck problems and systemic congestion (e.g., entire corridor rebuilds, multi-mile lane additions, and systemwide improvements) are far and above the focus of this program area. Unfortunately, when weighed against these larger, more visible projects, localized bottleneck problems often receive lower priority for funding or are put off entirely until they can be implemented as part of the larger, all-encompassing project. However, in this day and age of fiscal constraints, with agencies facing over-escalating costs and increasingly limited right-of-way, it is evident that "business as usual" in resolving congestion problems no longer applies. Low-cost bottleneck mitigations have several advantages that can help agencies deal with these developments:

  • They address current problems and therefore have high visibility. Agencies are under increasing pressure to do something immediately about congestion problems. Because low-cost bottleneck treatments are small in scale, they can be implemented quickly, so benefits start accruing immediately.
  • They are highly cost-effective and usually have positive safety impacts. Low-cost bottleneck treatments could mitigate or reduce crashes within weaving and merging areas, thereby increasing the cost-effectiveness relative to safety merits.
  • They will be required as transportation funding for megaprojects becomes more constrained. Major reconstruction projects are often justified as the only valid solutions to relieve congestion at the worst bottleneck locations. However, the cost of executing such projects is usually enormous. Low-cost bottleneck improvements provide an effective way to stretch scarce resources.
  • Lower cost means more locations can be addressed. More spot solutions can be implemented throughout a region, addressing more corridors than just a few large projects.
  • They are less invasive on the physical and human environments. The environmental footprint of low-cost bottleneck projects is very low, both in terms of disruptions during construction and final design.
  • They are not necessarily just short-term fixes. For some low-cost treatments, congestion benefits will play out over many years, not just a few. In fact, when combined with other forms of treatment (e.g., demand management and operations), they may be part of a long-term solution for a problem location or corridor.
  • They may be considered part of major reconstruction projects to address current problems. Some State DOTs have successfully incorporated low-cost bottleneck treatments within the context of larger, multiyear reconstruction projects.
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