By Greg Blake, Contributing Author
As the population of Austin, Texas continues to surge, the region’s transportation infrastructure has struggled to keep pace. Nowhere was this more evident than along the MoPac Expressway (also known as Texas State Highway Loop 1), where traffic had become a daily headache for commuters. Travel times on the southern section, between 35th Street and Loop 360 – a stretch of just 5 miles – jumped to 38 minutes during peak hours.
Recognizing the need for a solution, the Central Texas Regional Mobility Authority (Mobility Authority), a regional transportation agency responsible for developing and operating some of the toll roads in the Austin metro area, initiated the $10 million Barton Skyway Ramp Relief Project. It’s the first fully non-tolled roadway improvement project on a Texas Department of Transportation (TxDOT) owned road to be funded and managed by the Mobility Authority.
From the strong relationship developed with TxDOT to the timely and creative delivery of an effective, mobility improvement solution, this project has emerged as a model for future regional transportation initiatives.
Ramps of Relief
The MoPac Expressway is a vital transportation artery for the Austin metro area, connecting major employment and residential hubs in Austin, including downtown and the suburbs to the north and south.
Named after the Missouri Pacific Railroad, which originally owned the right-of-way, the controlled-access highway runs for approximately 31 miles, from State Highway (SH) 45 in the north to SH 45 SW in the south. It’s a mix of general-purpose lanes and express/toll lanes.
However, with population growth and regional development, the corridor has struggled with traffic congestion, especially during peak commute times.
For 12 years, between 2011 and 2023, Austin was the fastest growing large metro area in the country.
The current population is roughly 2.2 million as compared to 1.4 million in 2011. MoPac has been listed as one of Texas’ 100 Most Congested Road Sections (2024) by the Texas A&M Transportation Institute (TTI).
In 2020, the Mobility Authority procured an engineering consultant to conduct a traffic analysis to identify ways to relieve congestion along MoPac.
The Barton Skyway Ramp Relief Project was then developed to focus on a specific bottleneck area between Barton Skyway and Loop 360, which was identified in the analysis.
In 2021, the project transitioned to the engineering consulting firm, AtkinsRéalis, to take the lead on further design and implementation.
Subsequently, AtkinsRéalis engineers developed a schematic design that included a southbound auxiliary lane from Barton Skyway to Loop 360, an acceleration lane for the southbound Barton Skyway entrance ramp, three dedicated through-traffic lanes at Loop 360 and a dedicated left lane exit ramp for southbound Loop 360.
The Mobility Authority then hired another consultant partner to develop the final plans, specifications and estimates package for letting with oversight by AtkinsRéalis. Following TxDOT coordination and approval, as well as environmental studies, contractor procurement began in 2022, with the goal of beginning construction in early 2023.
Risk Assessments
A proactive risk analysis was performed, and it went well beyond the expected construction bid. Realistic budgets were developed, and there was a careful evaluation of what’s known and unknown about the project area and the proposed improvements.
The strategy incorporated appropriate contingencies for each phase of the project, including environmental, permitting, design, bidding and the construction phase. This allowed the team to proactively plan for and mitigate potential challenges through each phase.
Similarly, the team recognized the risk of construction extending past a single asphalt paving season during the development of the traffic control plan.
The Mobility Authority utilized permanent pavement sections for the temporary widening, ensuring a full-strength pavement section would be in place if the paving needed to be paused for winter.
This allowed the joint between the existing pavement and the temporary widening section to be relocated as needed to maintain all lanes of traffic during peak periods. All mill and inlay operations were performed overnight.
This disciplined, transparent approach to project budgeting and risk management proved critical on the Barton Skyway Ramp Relief Project during the transition from design to construction.
Disciplined Delivery
The general contractor, Dan Williams Company, earned bonuses for faster completion of work that required ramp closures. By opening these ramps to the public ahead of schedule, the contractor could receive an incentive bonus.
This incentive structure helped motivate the contractor to focus their efforts on expediting the work that most impacted the traveling public, thereby minimizing disruptions and ultimately delivering the project faster.
The strategy worked, and the contractor earned the maximum bonuses for meeting the ramp closure milestones and a significant portion of the substantial completion bonus, as well.
When the team encountered unexpected challenges, like issues with the existing lighting system, AtkinsRéalis worked with the contractor to develop feasible solutions that stayed within the original project budget. This involved bringing TxDOT, the Mobility Authority and the engineer of record together to develop solutions and stay within budget.
In August, the Mobility Authority celebrated completion of the Barton Skyway Ramp Relief Project.
With the project now complete, the congestion relief benefits are clear. Travel times have been dramatically reduced, and the chronic backups that once plagued the area are much improved. Since opening to traffic, these enhancements have reduced travel times by 30% on average, improved vehicle throughput by up to 47% and greatly reduced traffic merging conflicts at entrance ramps.
James Bass, director of the Mobility Authority Director, recently said in a statement that the completion of the Barton Skyway Ramp Relief Project represents a critical first step in addressing congestion along southbound MoPac.
“It also underscores the commitment by the Mobility Authority to re-invest toll revenue back into the Central Texas region by delivering equitable and accessible transportation solutions that benefit all drivers,” Bass said.
The Barton Skyway Ramp Relief Project is a testament to the power of innovative thinking and collaborative partnerships. By investing in this improvement on a TxDOT corridor, the Mobility Authority demonstrated its commitment to regional mobility beyond its own toll facilities – and it’s just the beginning. RB
Greg Blake is a vice president and senior division manager in Austin Texas for AtkinsRéalis.
