An Agency Guide on Overcoming Unique Challenges to Localized Congestion Reduction Projects

3.0 Case Studies of Successful Programs and Projects

3.1 Overview of Case Study Process

Much of the emphasis in this document to this point has been on identifying and describing barriers and challenges to implementing localized congestion (bottleneck) programs and projects. It is evident that while there is a wide range of barriers and challenges, many agencies have found ways to overcome them and implement programs and projects that are significantly successful and improving safety and mobility at relatively low cost. This section focuses on highlighting a variety of case studies that illustrate key principles and lessons on how the barriers and challenges were overcome.

The research team used an assortment of methods to gather information on the case study programs and projects, including an agency survey, attendance at LBR workshops, and a state-of-the-practice review of published studies and internet pages dealing with the subject of localized congestion and bottleneck removal projects.

Agency Survey

The research team conducted the research necessary to gather information for telling the story of the individual case-study examples that illustrate successful approaches and concepts for overcoming common barriers and challenges. The research was accomplished using a variety of means, including:

1. Internet searches,
2. Phone interviews, and
3. Electronic surveys.

The research team designed a short survey instrument to gather details regarding approximately forty potential case study projects where agencies implemented localized congestion relief projects. The survey collected information on:

• Project background: roadway description, type of improvement, cost and implementation date.
• Implementation barriers: checklist of common barriers with opportunity to provide original ideas.
• Strategies/methods for overcoming barriers: how were individual barriers overcome and what was the most difficult.
• Catalyst for project: was there an event or circumstance that caused the agency to address the localized congestion with a
  low-cost reduction project?
• Outcome assessment: what was the result (performance measurement, community reaction, awards/recognitions, etc.) of the reduction project?

State-of-the-Practice Review

The research team also performed a state-of-the-practice review to gather information on potential case study projects and programs. Internet searches and review of published literature and sources generated during workshops and state visits were the key information sources.

3.2 Case Study Matrix

The information gathered online was synthesized into the Overcoming Challenges Matrix shown in Table 8, which lists a number of case study examples where the most common challenges were overcome. The Overcoming Challenges Matrix provides one or more case study examples; however, detailed information was not available for all of these examples but a web link is provided in the outcome column in order to give readers a way to get additional information if it is desired. This document also contains a number of detailed case studies that are provided in the following subsections of Section 3 and also in Appendix A.

3.3 Detailed Case Studies

Table 9 lists the case study sites selected to illustrate key principles and lessons on how the barriers and challenges were successfully overcome. Each of the selected projects and programs demonstrates a somewhat unique approach and has practical value for agencies that want to start or expand an effort aimed at mitigating localized congestion resulting from bottlenecks. These sites also had sufficient information available — including their background, barriers, improvement strategies, circumstances, and outcome assessment — that made a detailed case study possible. The following subsections in Section 3 give a brief overview of the sites selected for detailed study. One-page summary fact sheets of the case studies are also provided in Appendix A.

Table 8. Overcoming Challenges Matrix ¹.

	Challenge Description	Case Studies	Outcome
Institutional	Having a project champion	Dallas, TX Kansas City, KN	+: 20+ projects due to DOT/MPO champions +: Governor passes bill allowing buses on shoulders
	Disposition towards mega projects	Minneapolis, MN Manchester, NH	+: Similar benefit for $7 vs. $138 million projects +: Expedited work at Exit 5 as part of mega project
	Project planning and programming requirements	Danbury, CT Austin, TX	+: Restriping at Exit 7 improved flow significantly +: Multi-disciplinary group mitigating congestion
	Lack of training/understanding on how to develop a successful project	Dallas, TX LBR workshops	+: Freeway Bottleneck Workshop +: Federal outreach workshops building consensus
	Knowledge of problem locations that can be fixed with low-cost solutions	Phoenix, AZ Dallas, TX Little Rock, AR	+: Regional bottleneck study +: Aerial freeway congestion mapping +: Operation Bottleneck program by MPO
	A culture of historical practices	Saginaw, MI	+: Successful roundabout at I-75/M-81 interchange
	Deficiency with internal and external coordination (design/operations)	New York, NY	+: PFI 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	Dallas, TX	+: Engineers performance evaluation includes bottlenecks
	Will the proposed solution work – lack of confidence	Florida DOT	+: Trial fix with cones made permanent with striping
Design	Design exception (DE) process is difficult	Pittsburgh, PA	+: New shoulder to avoid DE, Academy at I-279
	“Non-standard” design is considered a deal-breaker	Minnesota DOT	+: Creation of “flexible design” concept
	Problem is too big and nothing short of a rebuild will fix it	Plano, TX	+: Implement auxiliary lane on US 75 at SH 190
	Spot treatment will move problem downstream and not improve mobility	Renton, WA	+: SR 167 spot fix near Boeing reduces congestion
	Standard design practices contribute to bottleneck formation	Fort Worth, TX	+: I-20/SH 360 fix defies AASHTO basic lanes policy
Funding	There is no dedicated funding category for this type of project	Mississippi DOT Nebraska DOT	+: I-10 shoulder use after Katrina improves flow +: ITS funds for ramp gates to fix US 75 bottleneck
	Low-cost solution may blur or preclude need for bigger project	Dallas, TX	+: I-635 early action doesn’t stop $3B mega project
	Don’t understand if alternate funding categories can be used	Virginia DOT Ohio DOT	+: STARS program uses safety $ to target congestion +: Safety funds include congestion index
	Lack of available resources (e.g., DOT striping crews) for implementation	Dallas, TX	+: District striping contract implements small fixes
Safety	Hesitancy to implement solution that does not follow standard design	Minnesota DOT	+: Mobility crisis from I-35 bridge collapse
	Perception that safety is compromised with low-cost, non-standard fixes	Texas DOT	+: Average 35% crash reduction for 13 projects in TX
	Lack of shoulders takes away necessary refuge areas	Arlington, TX	+: Crash reduction at SH 360/Division
	Lanes that are not full width create safety issues for large trucks	Dallas, TX	+: I-30 Canyon truck rollovers basically eliminated

¹ For more details on these case studies, visit the informational links found in Appendix B. ↑

Table 9. Overview of Detailed Case Studies.

Case Study	Key Lesson Learned
Arkansas: Operation Bottleneck Program	“Ask and they will tell” → Active public involvement
California: I-580/US-101 Connector Ramp Restriping	“It is amazing what some white paint can do” → Low-cost restriping can really improve mobility
Louisiana: US-90 near Louisiana Superdome in New Orleans	“Sometimes less is more: creating exit-only lanes” → Eliminating a through lane can improve traffic flow
Maryland: Gateway Signal Optimization in Baltimore City	“Removing stops means more go’s” → Optimizing traffic signals can yield significant results
Michigan: I-75/M-81 Interchange Reconfiguration	“Michigan roundabout proves golden” → Innovative design saves $6 million and wins award
Minnesota: I-94 Lane Modification near Lowry Tunnel	“Providing options can smooth flow” → Providing drivers an option lane reduces congestion
Minnesota: TH-100 at St. Louis Park	“Smaller can sometimes equal bigger” → Small bottleneck fix has similar result to mega project
Missouri: I-44/Route 13 Diverging Diamond Interchange (DDI)	“The early bird gets the worm” → First DDI project tough to sell but worth the effort
Texas: Low-Cost Freeway Bottleneck Removal Projects	“Championing low-cost projects” → Many successful projects where champions were key

3.4 Arkansas Case Study

Metroplan MPO

Metroplan, the MPO for the Little Rock region, has implemented a program dubbed “Operation Bottleneck” aimed at identifying current congested locations that are amenable to relatively quick and inexpensive treatments. Major congestion problems – arterial corridors and freeway sections/interchanges with major capacity deficiencies – are well known throughout the area. Further, future (major) problems have been identified with the modeling done for the long-range transportation plan. However, funding for the major improvements necessary at these locations must come from either:

• State DOT, Arkansas State Highway and Transportation Department (they would be managed as state projects; and
• Local governments saving up several years of state and Federal allocations for a single project.

Metroplan wanted a way to serve their constituents better than constructing a scarce few megaprojects. Further, the region is almost in nonattainment for the eight-hour ozone standard. The text from their press release on the program sums up their intent very well:

“We’re aware of the major congestion issues in our area and have identified those in our long-range plans, but we know there are dozens, maybe hundreds of neighborhood problems throughout the region that could be fixed with something as simple as a roundabout or coordinating traffic signals to improve flow,” McKenzie says. “Localized problems like these can be harder to identify and are sometimes overlooked, even though they can be just as frustrating to drivers. Often they can be addressed much more quickly than larger projects. Those are the types of areas we are hoping to identify through Operation Bottleneck.”

Operation Bottleneck Program

Operation Bottleneck is largely based on the establishment of a Regional Mobility Authority (RMA). In Arkansas, an RMA is a coordinating body with no taxing powers – member counties would have to raise the taxes necessary to fund projects; multiple counties would be involved. Most likely, the RMA will be based on a temporary increase in local sales taxes county-by-county; they feel it is important to sunset the tax so it is more palatable to the public and elected officials. Metroplan hopes to leverage state and Federal funds against their self-generated revenue to fund the projects. Also key to the strategy is a specific list of projects to be funded by the tax increase, and most of the Operation Bottleneck effort has gone into project identification, as discussed below.

Project identification is being driven almost exclusively by public input via local meetings and an Internet survey. Metroplan also hired a marketing firm to promote the program through local media. Both congestion and safety problem areas are being solicited, along with other modal deficiencies (transit, special transportation). A huge range of responses has been received, from megaprojects to minor problems on local roads. For congestion problems, signals and interchanges are dominating the responses. Safety problems identified by the public tend to be more general than site-specific. (This is understandable since congestion is experienced routinely but crashes are rare events for individuals.)

Metroplan staff will assemble the projects and will develop a list of projects to iterate with the public. Staff will also make revenue projections under different sales tax rates. No formal benefits assessment is planned – as with project identification Metroplan emphasized that public input is the driver for Operation Bottleneck, not technical processes (which they use for all other transportation planning activities). The staff will compare public-identified projects with those in the TIP and LRTP as well as against congested sections identified in their Congestion Management System in developing a prioritized list. Metroplan staff offered two types of improvements that are likely to dominate the project list:

• Low-cost arterial improvements – improved timing, intersection approach geometric improvements, and access management; and
• Roundabouts at uncontrolled, stop sign-controlled, or low volume signal locations.

Initial results were presented to public officials in October 2008. Metroplan would like to make this an ongoing process, especially since the public support for the program has been very high. How to structure the funding for an ongoing program will be tricky, however. Metroplan staff highlighted a $1.5 million dollar improvement project implemented in 2010 that alleviated intersection congestion at Dave Ward Drive and Donaghey Road in Conway, Arkansas as an effective outcome of the Operation Bottleneck program. Table 10 outlines the key barriers and challenges and how they were overcome.

Table 10. Synopsis of Operation Bottleneck – Dave Ward Drive/Donaghey Road Case Study.

Barriers and Challenges	How They Were Overcome
Other – congestion at intersection located near college, major intersection improvements proposed required additional right-of-way	Project in part associated with proposed development
Other – federal funds were first proposed for project, funds were shifted and all local money was used on the project	City identified local funding to be used on the project, with the limited federal funding being placed on another project that included federal funds

For More Information

See the fact sheet in Appendix A for a synopsis of the Operation Bottleneck case study.

3.5 California Case Study

Caltrans

The California Department of Transportation (Caltrans) does not have a formal bottleneck planning process; rather, bottleneck issues are addressed at the district level as part of their Corridor System Management Plans (CSMP), which are developed for some of California’s most congested transportation corridors. System monitoring and evaluation is seen as the foundation for the entire process because it cannot only identify congestion problems, but also be used to evaluate and prioritize competing investments. The CSMP includes the identification of bottlenecks and potential short-term fixes as part of an overall and long-term strategy for making corridor improvements. This may take the form of an “LBR audit,” which is a review of traditional large-scale corridor studies to identify opportunities for using LBR improvements as part of the package of improvements. The LBR audit concept is similar to that of Road Safety Audits. Caltrans does not have a direct funding for bottlenecks, although bottleneck projects are routinely programmed through the CSMP process.

I-580/US-101 Connector Ramp Restriping

The second detailed case study is a project in California that involved restriping a ramp to improve traffic flow. Table 11 outlines the key barriers and challenges and how they were overcome.

Table 11. Synopsis of I-580/US-101 Connector Ramp Restriping Case Study.

Barriers and Challenges	How They Were Overcome
Project champion	Public became champion due to organized outcry
Lack of confidence in proposed solution	Confidence from knowledge that this was a temporary solution.
Low-cost spot solution may blur the need for larger project	Still went forward with $10 million project for permanent widening of the ramp to two lanes
Lack of shoulders takes away necessary refuge areas	Loss of shoulders only a temporary condition

For More Information

See the fact sheet in Appendix A for further details of the I-580/US-101 Connector Ramp Restriping case study.

3.6 Louisiana Case Study

Louisiana Department of Transportation and Development

The Louisiana Department of Transportation and Development (DOTD) does not current have a formal localized bottleneck reduction program for project implementation. Low-cost projects that address localized congestion are done on an ad hoc basis within the various district offices.

US-90 near Louisiana Superdome in New Orleans

The fourth case study is a project implemented by the Louisiana DOTD in the New Orleans area on US-90, also commonly referred to as the Ponchartrain Expressway (PE). This project is unique because it is a case where DOT officials decided to eliminate through lanes on the PE to create exit-only lanes designed to reduce last-second merging and ease the chronic bottleneck. Table 12 outlines the key barriers and challenges and how they were overcome.

Table 12. Synopsis of the US-90 near the Louisiana Superdome in New Orleans Case Study.

Barriers and Challenges	How They Were Overcome
Lack of confidence in the proposed solution	DOTD staff performed a before study to get traffic volumes and determine that the reduction from 3 to 2 through lanes was not going to create another bottleneck in order to ease fears of management staff
Spot treatment will move the problem and not fix it	DOTD staff agreed to perform an after study to assess the operational outcome and make sure the bottleneck did not just move downstream

For More Information

See the fact sheet in Appendix A for a synopsis of the US-90 near Louisiana Superdome in New Orleans case study.

3.7 Maryland Case Study

Maryland State Highway Administration

The Maryland State Highway Administration (SHA) has a dedicated program of about $5M per year for the identification and implementation of low-cost traffic congestion improvements at intersections. The program’s genesis tracks to when SHA asked, “What can be done if and when a megaproject’s ‘no‑build’ alternative is chosen?” The program has been well received by the public and local governments. Projects typically include low-cost projects that can be implemented quickly, such as signal timing upgrades and adding turn lanes and through lanes at intersections. The Maryland SHA also has had considerable success with projects to improve freeway ramps and merge areas that have reduced congestion bottlenecks at a low cost.

Baltimore City Gateway Signal Optimization

The fifth case study is a project implemented in Baltimore City, Maryland involving optimization of traffic signals in nine regionally significant arterial corridors. The signal retiming was implemented for less than half a million dollars and produced an overall benefit-to-cost ratio of 51:1 based on benefits accrued from reductions in vehicle delay, number of stops, fuel consumption, and particulate emissions. Table 13 outlines the key barriers and challenges and how they were overcome.

Table 13. Synopsis of the Baltimore City Gateway Signal Optimization Case Study.

Barriers and Challenges	How They Were Overcome
Lack of training	City staff hired a consultant with experience in corridor signal timing projects
Culture of historical practices	Prior to the project the City signal shop had a lot of control over signal timings; however, majority control was switched to engineering
No dedicated funding category	City obtained funding using the CMAQ program in additional to local funds
Lack of available resources	Hiring a consultant supplemented available City staff

For More Information

See the fact sheet in Appendix A for a synopsis of the Baltimore City Gateway Signal Optimization case study.

3.8 Michigan Case Study

Michigan DOT

Michigan DOT currently is in the process of developing a structured Localized Bottleneck Reduction (LBR) Program. The effort began several years ago with structured changes at MDOT, during which MDOT officially reorganized their Maintenance and Traffic and Safety Divisions to create a Division of Operations. The next step was the formation of a new section titled Systems Operations and Management (SOM). One of their early charges was to develop an approach to identify and eliminate bottlenecks throughout the State. Several years previous to this reorganization, MDOT developed and utilized a “Choke Point” Program, and their current efforts are patterned after that effort.

One of the first official action steps that the SOM Section pursued was to solicit potential bottleneck locations and problem descriptions from each of their seven region offices. More than 200 locations were identified, with about one-third being freeway interchanges. Based on further review by the SOM Section, the total number of potential locations was reduced to approximately 125 locations, which they believed: 1) met their definition of a “bottleneck” location; and 2) had a potential cost-effective solution that could address the problem. One of the primary goals of this highly focused initial effort is to develop a documented and sustainable approach that can demonstrate excellent benefit-to-cost ratios, as well as justification for allocation and expenditure of funds on the statewide LBR Program. The underlying goal was to obtain leadership support and a dedicated funding template specifically for bottleneck reduction projects, which has now been achieved.

Many challenges exist as the Program and structure move forward. One primary challenge is the need to complete a detailed analysis necessary for a large number of potentially competing projects, as well as a freeway analysis of these projects. MDOT staff resources are limited and MDOT is reviewing the potential use of consultants and/or universities for project analysis. Another issue is how to justify and evaluate the impacts of the suggested changes as well as the existing problem. The intent is to create a level playing field for application of LBR funding by each of the seven regions. The third major challenge is the availability of funding. Michigan is going through an extremely dynamic period with the overhaul of the automobile industry, and their funding has been reduced. These issues are all being discussed and debated as MDOT moves forward to establish and document a formal, fully funded LBR Program.

I-75/M-81 Interchange Reconfiguration

The sixth case study is a project implemented in Saginaw, Michigan involving a reconfiguration of the I-75/M-81 interchange from a diamond to a modern roundabout. Given limited resources, the Michigan DOT chose to use an innovative design approach with roundabouts replacing the tight diamond. Table 14 outlines the key barriers and challenges and how they were overcome.

For More Information

See the fact sheet in Appendix A for a synopsis of the I-75/M-81 Interchange Reconfiguration case study.

Table 14. Synopsis of I-75/M-81 Interchange Reconfiguration Case Study.

Barriers and Challenges	How They Were Overcome
Culture of historical practices	Local DOT staff had a focused discussion with management on the design concept – and the approximately $6 million dollar cost savings
Lack of confidence in proposed solution	Used a microscopic simulation model to analyze the roundabout solution and show a level-of-service (LOS) improvement from D to A
Other: getting stakeholder buy-in	Performed presentations to stakeholders and used an aggressive public involvement and education campaign including the use of special brochures, videos and newspaper editorials.

3.9 Minnesota Case Studies

Minnesota DOT

Minnesota DOT was originally driven to explore low-cost congestion relief projects because of budgetary restrictions, but soon realized that these projects could be implemented very quickly and, as a bonus, were highly visible and popular with the public. In less than one year, the Minnesota DOT developed a highly accelerated process for bottleneck identification and prioritization, which led to many effective projects in the following two years. The Minnesota DOT also found that because of lower costs, it could identify multiple locations throughout the region and “spread around” bottleneck projects in an equitable way. This process consisted of a study that used a five-step process to narrow potential projects into a recommendation list to the state legislature. Evaluation of completed projects produced high benefit/cost ratios, usually greater than 8:1.

Note: Circa 2009, this one-time activity was replaced by an ongoing CMS process known as the Congestion Management Planning Process, which has been formally adopted as part of the 3C planning process.

I-94 Lane Modification near Lowry Tunnel

The seventh case study is a project implemented in Minneapolis, Minnesota involving a lane modification near the Lowry Tunnel. The Minnesota DOT implemented a relatively low-cost ($300,000) project to provide an option lane on westbound I-94 approaching the I-394 interchange in proximity to the Lowry tunnel. This is a relatively recent project (September 2010) that is still being assessed by DOT staff. Table 15 outlines the key barriers and challenges and how they were overcome.

Table 15. Synopsis of I-94 Lane Modification near Lowry Tunnel Case Study.

Barriers and Challenges	How They Were Overcome
Culture of historical practices	Education on benefits in short-term goals.
Lack of confidence in solution	Review of traffic analysis and other data supports the solution.
Spot treatment won’t fix the problem	Commitment to monitor for one year and make necessary changes with future programmed project one year out.
Hesitancy to implement non-standard solution	Review of standards and how project does not violate driver expectation and, where design exception needed, determine likely outcomes.

TH-100 at St. Louis Park Project

The eighth case study is a second project implemented in Minneapolis, Minnesota involving improvements to a section of Trunk Highway 100 (TH-100) between 36th Street and I-394. The Minnesota DOT implemented a $7.1 million dollar project to add a third travel lane in one of the metro areas worst bottlenecks by converting roadway shoulders. This project was completed in 2006 and then won an award for Public Project of the Year in Minnesota because of the significant mobility improvement. Table 16 outlines the key barriers and challenges and how they were overcome.

Table 16. Synopsis of TH-100 at St. Louis Park Project Case Study.

Barriers and Challenges	How They Were Overcome
Culture of historical practices	Education on benefits in short-term goals.
Lack of confidence in solution	Review of traffic analysis and other data supports the solution.
Spot treatment won’t fix the problem	Commitment to monitor for one year and make necessary changes with future projects.
Hesitancy to implement non-standard solution	Review of standards and how project does not violate driver expectation and, where design exception needed, determine likely outcomes.

For More Information

See the fact sheets in Appendix A for a synopsis of the I-94 Lane Modification near Lowry Tunnel and TH-100 at St. Louis Park Project case studies.

3.10 Missouri Case Study

Missouri DOT

The Missouri DOT does not currently have a formal localized bottleneck reduction program. Low-cost projects that address localized congestion are done on an ad hoc basis within the various district offices – most notably in the Springfield and St. Louis metropolitan areas. The Missouri DOT utilized a “practical design” concept in the fall of 2005 that challenged internal staff, the FHWA and consulting community to help cut the budget of the 5-year STIP by 10 percent. Engineers were told that they could put their design manuals on the shelf for a year and be guided by the following three rules:

1. Safety – every project must get safer. There is no room for compromise where safety is concerned.
2. Communication – there is collaboration in developing practical solutions.
3. Quality – the practical solution must function properly and cannot leave a legacy of maintenance challenges.

The District challenge resulted in an initial savings of over $400 million across the 5-year STIP. District representatives were assembled to discuss their experiences with practical design – both good and bad. About 400 ideas and comments were discussed and documented and then boiled down to 25 broad policies in 5 general areas. These five areas accounted for 80 percent of the Missouri DOTs program delivery expenditures:

• Paving and based – 35 percent;
• Bridges – 17 percent;
• Grading – 11 percent;
• Right-of-way – 10 percent; and
• Traffic control – 7 percent.

The switch to the practical design concept in Missouri has produced a significant organizational change and also positive results in the safety, communication and quality as shown in Table 17.

Table 17. Outcome of Missouri DOT Organizational Change to Practical Design Concept.

Category	Outcomes
Safety	Largest drop in traffic-related fatalities of any state in the nation in 2006 Fatal crashes dropped below 1,000 in 2007 and still further in 2008. 11% decrease in run-off-road crashes since 2004
Communications	90% of newspaper editorials in 2008 were positive Customer satisfaction with Missouri DOT rose to 78% in 2008 95% of customers believe projects are the right transportation solution
Quality	Since 2002, Missouri DOT has delivered a $7 billion dollar program 0.4% under budget

I-44/Route 13 Diverging Diamond Interchange

The ninth case study is a first of its kind implemented in Springfield, Missouri. The Missouri DOT implemented a $3.2 million dollar project to convert an existing congested interchange (I-44/Route 13) into the first Diverging Diamond Interchange (DDI) in the United States. The first DDI was somewhat of a battle to get in place but its success is leading to more implementations in Missouri. Table 18 outlines the key barriers and challenges and how they were overcome.

Table 18. Synopsis of I-44/Route 13 Diverging Diamond Interchange Case Study.

Barriers and Challenges	How They Were Overcome
Project champion	The project engineer became champion and garnered by internal (upper DOT management) and external (business) support.
Project planning and programming requirements	The FHWA required that a modified Interstate Access Justification (IAJ) be done 2 weeks before the project was let; however, project staff was able to finish the new analysis prior to the deadline.
Lack of confidence in the proposed solution	Project staff utilized an enhanced level of traffic analysis and public outreach (particularly with Wal-Mart) including a simulation model and project video designed to showcase how a DDI operates.
Hesitancy to implement solution that does not follow standards	The project engineer had to convince DOT Central Design staff that the pedestrian access would work well through the middle of the DDI instead of on the outside like traditional diamonds.

For More Information

See the fact sheet in Appendix A for a synopsis of the I-44/Route 13 Diverging Diamond Interchange case study.

3.11 Texas Case Study

Texas DOT

The Texas DOT does not currently have a formal localized bottleneck reduction program. Low-cost projects that address localized congestion are done on an ad hoc basis within the various district offices – most notably in Austin (see Table 19) and Dallas/Fort Worth (see Table 20).

Texas Low-Cost Freeway Bottleneck Removal Projects

The tenth case study is of a low-cost freeway bottleneck removal program primarily in the DFW metropolitan area. The Texas DOT implemented a number of low-cost projects to address localized congestion. Most projects utilized improvements such as restriping, shoulder conversion, and installation of auxiliary lanes to improve mobility in short sections of freeway. Most improvements were implemented with local DOT discretionary funds, and projects champions at both the DOT and MPO were a key to success. Table 21 outlines the key barriers and challenges and how they were overcome.

Table 19. Summary of Seven Bottleneck Removal Projects in Austin, Texas.

Project Location	Implemented Improvements
I-35 NB at Parmer Lane	Supplemental lane was added from the Parmer Lane entrance to the Dessau exit and then extended to Wells Branch Parkway.
I-35 SB at Wells Branch Parkway	Closed Dessau Road entrance to southbound (SB) I-35 and added an auxiliary lane from the Wells Branch entrance to the Parmer Lane exit.
I-35 NB at US 183	Added an auxiliary lane from US 183 to the Braker Lane exit ramp.
I-35 SB at US 183	Began a 4th lane for SB I-35 at the Rundberg entrance (instead of the US 183 direct connector) and extended the auxiliary lane from the US 183 frontage entrance to the US 290 exit upstream so that it begins at the direct connector. The US 183 entrance from the SB I-35 frontage road was closed in order to facilitate flow along the auxiliary lane.
I-35 SB at Riverside Drive	Added an auxiliary lane from the Riverside Drive entrance to the Oltorf Road exit.
Loop 1 SB at Far West Boulevard	Added an auxiliary lane from the Far West Boulevard entrance to the Ranch-to-Market 2222/Northland exit ramp.
Loop 1 at Loop 360	Realigned the SB Loop 1 main lanes so that the lane drop occurs at Loop 360 East rather than at the Loop 360 West exit ramp. Upstream of this lane drop are the high-volume Bee Caves Road entrance and the low-volume Barton Skyway entrance ramp to SB Loop 1.

Table 20. Evaluation of Thirteen Texas Bottleneck Projects –
Mostly in Dallas-Fort Worth.

District	Freeway(s) and Limits	Improvement Type	Annual Benefit	Cost	B-C Ratio*
FTW	NB Sh460 @Division (SH180)	Shoulder conversion (outside) + auxiliary lane addition	$200,000	$150,000	10:1
ELP	EB I-10 @ US54	Restriping + ramp modification + auxiliary lane addition	$1.3M	$530,000	20:1
DAL	EB I-30 I-35E to I-45	Ramp reversal (exit converted to entrance) + auxiliary lane addition	$700,000	$660,000	9:1
DAL	NB I-35E I-30 to Dallas North Tollway	Shoulder conversion (inside) + auxiliary lane additions	$600,000	$130,000	37:1
DAL	EB SH190 to SB US75	Restriping + ramp modification	$500,000	$11,000	374:1
DAL	NB I-35E ramp to Dallas North Tollway	Re-striping + ramp modification	$300,000	$20,000	132:1
DAL	NB-SB I-35E Loop 12 to I-635	Shoulder conversion (inside) + removal of two inside merges	$11.0M	$1.9M	47:1
DAL	WB I-30 ramp to SB I-35E	Restriping + ramp modification	$200,000	$5,000	324:1
FTW	EB I-20 to NB Sh460	Restriping + ramp modification + removal of thru lane inside interchange	$500,000	$10,000	400:1
FTW	SB Sh460 to WB I-20	Restriping + ramp modification + removal of thru lane inside interchange	$30,000	$8,000	32:1
FTW	SB Sh460 @ Division (SH180)	Ramp closure + auxiliary lane addition	$1.0M	$440,000	18:1
DAL	EB I-635 to NB US75	Restripe and widen left-side ramp from one to two lanes	$3.6M	$2.45M	24:1
DAL	SB US75 to WB I-635	Shoulder conversion (inside) on I-635 to allow ramp from US75 its own lane	$3.8M

^* B-C ratio based on ten-year project life with a 4 percent discount rate ↑

Table 21. Synopsis of Texas Low-Cost Freeway Bottleneck Removal Projects Case Study.

Barriers and Challenges	How They Were Overcome
Project Champion	Support for low-cost bottleneck projects was at a high level, including the District Engineer and MPO Director.
Project planning and programming requirements	Most solutions were over a short distance where air quality and environmental requirements were not necessary.
Lack of training	The Texas Transportation Institute developed a Freeway Bottleneck workshop that taught the DOT about successful bottleneck removal.
Lack of incentives/recognition	DOT leadership formalized recognition for successful projects, rewarding Area Engineers during annual performance evaluations.
Design exception process is difficult	Over time, DOT gained the trust of FHWA staff by evaluating projects and showing the positive operational and safety benefits.

For More Information

See the fact sheet in Appendix A for a synopsis of the Low-Cost Freeway Bottleneck Removal Projects case study.