Recurring Traffic Bottlenecks: A Primer
Focus on Low-Cost Operational Improvements (Fourth Edition)
Chapter 4. How to Structure a Localized Bottleneck Program
What is Stopping Us from Fixing Bottlenecks?
States have cited a number of barriers to establishing bottleneck-specific or similar programs that target chokepoint congestion:
- Predisposition for large scale, long-term congestion mitigation projects. Traditional transportation planning and programming efforts are often predisposed toward major capital improvement projects to relieve congestion such as corridor-widening or massive reconstruction of an interchange. There is also no shortage of demand management strategies designed to fight the congestion battle, such as high occupancy vehicles (HOV), tolling and pricing, transit alternatives, and ridesharing programs. But the onerous processes involved in many of these initiatives can squeeze out smaller programs.
- Lack of program identity. Unless there is a formal program identity, bottleneck remediation is usually relegated to a few projects completed as part of an annualized safety program, or as a subordinate part of larger, other purposed projects.
- Lack of a champion. Many successful State or metropolitan planning organization programs are the result of one or more persons taking charge to either mandate or adopt a program. High-level administrators often set the policy direction and strategic initiatives for their agencies, while midlevel managers' production reflects their priorities and skills in executing those initiatives.
- Lack of resources. Many State agencies are finding themselves overworked and understaffed. Although the return on investment for Localized Bottleneck Reduction (LBR) projects are high, agencies often do not have the in-house resources necessary to conduct detailed analyses required to evaluate and prioritize the large number of potentially competing projects. With limited resources, agencies are relegated to hiring consultants and/or universities to conduct detailed project analysis.
- Lack of funding. With many State agencies experiencing major budget shortfalls, lack of funding continues to be an often cited barrier to implementing new programs.
- Responsibility has not been assigned. Not part of ongoing planning and programming processes. Localized bottleneck mitigation projects are not often included in the ongoing planning and programming processes for most agencies. Others struggle with how best to identify problem locations, assess existing conditions, and quantify the impacts of proposed remedies, as there is no structured process in place. For example, in developing their structured LBR program, the Michigan Department of Transportation (DOT) cited challenges regarding how best to justify and evaluate project impacts while creating a level playing field for application of LBR funding across each of their seven regions.
- A culture of legacy practices. Many agencies face institutional challenges in changing their current business practices. For example, one agency dutifully executed an annualized "safety" program and looked only at crash rates in determining their annual top 10 list of projects. After instituting a congestion mapping process, they identified several significant stand-alone chokepoints that did not correlate with their high-crash mapping. Thereafter, high-congestion hot spots competed with high-accident hot spots on their unified top 10 list of projects. In addition, even if there is agreement that an LBR should exist, barriers often exist for implementing specific projects, including:
- Design challenges. LBR treatments may sometimes require "nonstandard" designs. Seeking exceptions to design standards is often tedious with no guarantee that they will be approved.
- Safety challenges. Even if design issues are resolved, safety issues may still be present. For example, eliminating a shoulder to obtain an extra through lane may have safety implications.
By proactively addressing as many of the above barriers as possible, State and regional transportation agencies can work to establish an annualized LBR program identity that gives congestion hot spots the appropriate level of consideration and attention relative to other transportation improvement programs.
Overcoming Challenges to Implementing Localized Bottlenecks Reduction Projects
The Federal Highway Administration (FHWA) publication, An Agency Guide on Overcoming Unique Challenges to Localized Congestion Reduction Projects, provides more guidance for agencies wishing to implement an LBR program (Figure 5). This report presents and describes examples of institutional, design, funding, and safety challenges that agencies face when trying to develop unique solutions to localized congestion problems. The main questions that this guidance helps an agency address are below.
- What are the most common barriers and challenges with addressing localized congestion problems?
- What are some case study examples that highlight how barriers and challenges have been overcome?
- What are some of the key factors in successful implementation of localized bottleneck projects?
Through a series of case studies, documented in An Agency Guide on Overcoming Unique Challenges to Localized Congestion Reduction Projects, States and metropolitan planning organizations (MPO) have developed innovative ways to overcome the common barriers to LBR projects. The case studies identified the most common barriers and challenges associated with addressing localized congestion problems and the key factors in successful implementation of localized bottleneck projects.
Figure 5. Photo. Cover of Federal Highway Administration's An Agency Guide on Overcoming Unique Challenges to Localized Congestion Reduction Projects.
(Source: Federal Highway Administration.)
Table 2. Examples of how agencies have addressed localized bottleneck issues.
|Having a project champion.
Kansas City, KN
|+: 20+ projects due to agency champions.
+: Governor passes bill allowing buses on shoulders.
|Disposition towards megaprojects.
|+: Similar benefit for $7 million versus $138 million projects.
+: Expedited work at Exit 5 as part of megaproject.
|Project planning and programming requirements.
|+: Restriping at Exit 7 improved flow significantly.
+: Multidisciplinary group mitigating congestion.
|Lack of training/understanding on how to develop a successful project.
|+: Freeway Bottleneck Workshop.
+: Federal outreach workshops building consensus.
|Knowledge of problem locations that can be fixed with low-cost solutions.
|+: Regional bottleneck study.
+: Aerial freeway congestion mapping.
+: Operation Bottleneck program by MPO.
|A culture of historical practices.
|+: Successful roundabout at I‑75/Michigan 81 interchange.
|Deficiency with internal and external coordination (design/operations).
|New York, NY
|+: Functional groups.
|Can't implement projects without being in approved regional/State plans.
|Rhode Island DOT
|+: Creation of the Strategically Targeted Affordable Roadway Solutions (STARS) program.
|No incentive or recognition for successful low-cost bottleneck reductions.
|+: Engineers performance evaluation includes bottlenecks.
|Will the proposed solution work?—Lack of confidence.
|+: Trial fix with cones made permanent with striping.
|Design exception (DE) process is difficult.
|+: New shoulder to avoid DE, Academy I‑279.
|"Nonstandard" design is considered a deal-breaker.
|+: Creation of "flexible design" concept.
|Problem is too big and nothing short of a rebuild will fix it.
|+: Implement auxiliary lane on U.S. 75 at SH 190.
|Spot treatment will move problem downstream and not improve mobility.
|+: SR 167 spot fix near Boeing reduces congestion.
|Standard design practices contribute to bottleneck formation.
|Fort Worth, TX
|+: I‑20/SH 360 fix defies Americans Associated of State and Highway Transportation Officials (AASHTO) basic lanes policy.
|There is no dedicated funding category for this type of project.
|+: I‑10 shoulder use after Katrina improves flow.
+: ITS funds for ramp gates to fix U.S. 75 bottleneck.
|Low-cost solution may blur or preclude need for bigger project.
|+: I‑635 early action doesn't stop $3 billion megaproject.
|Don't understand if alternate funding categories can be used.
|+: STARS program uses safety funds to target congestion.
+: Safety funds include congestion index.
|Lack of available resources (e.g., DOT striping crews) for implementation.
|+: District striping contract implements small fixes.
|Hesitancy to implement solution that does not follow standard design.
|+: Mobility crisis from I‑35 bridge collapse.
|Perception that safety compromised with low-cost, nonstandard fixes.
|+: Average 35 percent crash reduction for 13 projects in Texas.
|Lack of shoulders takes away necessary refuge areas.
|+: Crash reduction at SH 360/Division.
|Lanes that are not full width create safety issues for large trucks.
|+: I‑30 Canyon truck rollovers basically eliminated.
(Source: Federal Highway Administration.)
Ideas for Structuring a Localized Bottleneck Reduction Program
There are no set guidelines for establishing an LBR program and no two programs will look the same. State DOTs, MPOs, or local transportation agencies are the traditional organizations who lead LBR efforts as part of larger missions of the organization. Many times, the State may identify bottlenecks and work closely with MPOs to integrate these projects into the Transportation Improvement Plan (TIP) and other targeted funding sources such as Congestion Mitigation and Air Quality (CMAQ) and safety. Other times, low-cost bottlenecks can be addressed programmatically at the State DOT level by reviewing existing plans and programs and looking for opportunities to include LBR improvements and strategies. Examples of how transportation agencies have structured LBR programs include the following:
Periodic Special Program or Initiative
In 2007, the Minnesota DOT was asked by the State legislature to develop a rapid turnaround plan to identify low-cost, quickly implementable projects that were not already identified by the traditional planning and programming processes. In a matter of months, this unique approach led by the traffic management center engineers basically "brainstormed" low-cost, candidate projects that were nagging problems, but for whatever reasons, had never landed on traditional capital improvement programs. Starting with over 150 ideas, the panel met monthly on a fast track. Each time they met they would reduce by half the list of candidate projects until they finally reached consensus on a few projects that were deemed to have the highest benefit returns and also fit within the given budget. One of the final projects was picked by the local newspaper as the "public works project of the year" since it concurrently solved a years-old problem with a relatively low-cost and quick turnaround solution—as in, "why didn't anyone think of this before?" Similarly, in 2008, the Central Arkansas MPO undertook "Operation Bottleneck," a campaign to openly solicit public input of candidate locations, although the program had a finite life span to implement. Both of these examples show how a little ingenuity and maybe some out-of-the-box brainstorming can overcome traditional stovepipe thinking.
Incorporating Bottlenecks into Other Programs
At the State DOT level, low-cost bottlenecks can be addressed programmatically even without a special program or initiative. One approach is to conduct a review of existing plans and look for opportunities to include LBR improvements in them. For example:
- The California DOT (Caltrans), Corridor Management Process. Caltrans, as part of their Corridor Management Process, includes the identification of bottlenecks and potential short-term fixes as part of an overall and long-term strategy for making corridor improvements.
- The Ohio DOT, Federal Hazard Elimination Program. The Ohio DOT added a congestion-based index ranking to their annual identification of spot safety problems for the Federal Hazard Elimination Program (HEP).
- The Washington State DOT, Moving Washington Initiative. The Washington State DOT recognizes bottlenecks and chokepoints as an integral part of their project planning and development process. The recent Moving Washington initiative incorporates LBR concepts into a coordinated program to address congestion. At the planning stage in their Highway System Plan, the WSDOT considers bottlenecks together with traditional corridor improvements under the "Congestion Relief" category. Congestion relief projects are ranked using the benefit/cost ratio, contribution to performance goals, and other qualitative factors, and compete on these bases with projects in other categories in the Highway System Plan: Preservation, Safety, Environmental Retrofit, Economic Vitality, and Stewardship.
- Metropolitan Planning Organization Congestion Management Process. At the MPO level, the short-term nature of LBR projects meshes well with the Congestion Management Process (CMP). As planners' perspectives broaden to include this shorter-term view of the system (in addition to the traditional long-range view), an LBR program makes perfect sense from a planner's viewpoint, LBR improvements would be another aspect of the CMP process. Because an LBR program should be data- and performance- driven, it is a logical complement to a CMP; the same data should be used for both purposes. In fact, within the context of the CMP, it may useful to make the two processes seamless, at least at the MPO level.
Formal Low-Cost Bottleneck Improvement Programs
Another option is to establish a defined bottleneck program within the agency, as illustrated by the following examples:
- The Colorado DOT "Colorado Bottleneck Reduction Assistance" (COBRA). In 2014 the Colorado DOT (CDOT) established the Corridor Operations and Bottleneck Reduction Assistance (COBRA) program, which identifies and implements operations improvements for State corridors to address localized bottlenecks and other operational improvement opportunities. The COBRA program is formalized, with a dedicated director as well as documented goals, objectives, and a weighting system for prioritizing projects based on these goals and objectives. The COBRA program also has a formally scheduled cycle for submitting, funding, and delivering projects. Since 2014, the COBRA program has identified well over 100 projects and prioritized them based on the weighting system—and this number continues to grow as the COBRA program works towards cost-effective solutions to operational bottlenecks.
- Virginia's and Rhode Island's Programs. Other examples include the Virginia DOT (VDOT) Strategically Targeted Affordable Roadway Solutions (STARS) Program, which is a safety and congestion program that partners State, planning district and local transportation planners, traffic engineers, safety engineers, and operations staff to identify "hot spots" along roadways where safety and congestion problems overlap and are suitable for short-term operational improvements. As new construction or growth occurs in a corridor, the STARS plan for that corridor is infused into the overall public improvements. Also, as periodic funding is released, the STARS projects stand as "shovel ready" projects. Following the VDOT's success, the Rhode Island DOT (RIDOT) modeled its own version of the VDOT's STARS program to meet its own low-cost bottleneck program needs.
Potential Issues with Localized Bottleneck Reduction Treatments
In addition to barriers that inhibit the creation of a LBR program, issues related to implanting LBR strategies also exist. Agencies have cited the following barriers associated with LBR strategies:
- Compliance with State Implementation Plans for Air Quality Conformity. State Implementation Plans (SIP) set forth the State's strategy for getting its air quality within National Ambient Air Quality Standards (NAAQS) and keeping it there. They include a large variety of project types, including transportation projects, and extensive emissions modeling is undertaken to estimate their impact. There is a great deal of uncertainty as to how an LBR project might affect the SIP: does the entire SIP have to be redone, does emissions modeling just for the LBR project have to be performed, or can the emissions impacts be assumed to be small enough that they can be ignored? Such occurrences must be dealt with on a case-by-case basis by agencies wishing to undertake bottleneck projects. One point worth noting: if air quality conformity in a location precludes or discourages major capital expansion (e.g., additional lane-miles), the type of improvements in a localized bottleneck program clearly do not fall in this category.
- Compliance with Long-Range "Design Concepts." In some cases, a design concept or goal has been formally established for a roadway or corridor, with the idea that any improvements should be part of that concept. When the design concept is institutionalized, it may be difficult to deviate from it with an LBR treatment that does not match. Agencies must decide and weigh the benefits/costs of doing smaller bottleneck solutions in the short term against the benefits/costs of waiting for a more complete solution. This decision can be difficult, especially for agencies without a good appreciation for the typical benefits and costs of smaller bottleneck solutions and how long those benefits might last.
- Compliance with Design and Safety Standards. LBR treatments tend to be of a smaller scale than typical capital improvement projects. This means that the redesign is usually not made to existing design standards, which depending on the funding source, may require a formal design exception. Further, even if a design exception is not needed, safety problems may be introduced by the LBR treatment, especially if the identified problem is congestion-oriented. To address this issue, LBR treatments need to be assessed for potential safety impacts prior to implementation. Also, a Roadway Safety Audit of the design would be beneficial. Based on the review, additional mitigation of safety impacts may be warranted, or a close monitoring of crash experience at the site may be used. Finally, agencies should be in contact with the FHWA division offices throughout the process as design review may be required, depending on circumstances.