City of Austin and I-35 Capital Express Projects

The I-35 expressway through the heart of Austin and Central Texas is being reconstructed to address safety, mobility and east-west connectivity needs. The Texas Department of Transportation is leading the project to make improvements to I-35 in Travis County from SH 45 North to SH 45 Southeast. This page provides details of the City of Austin's role and involvement in partnership with TxDOT to achieve this vision, and how you can participate, as well.

About the I-35 Capital Express projects
About TxDOT I-35 Capital Express Projects

I-35's Austin-area section carries nearly 200,000 vehicle trips per day, 85% of which are local to the region. The roadway has evolved since its construction in the 1950s to become a critical mobility link connecting Austin, Central Texas and beyond.

The highway's construction and current design on top of East Avenue also had consequences, becoming a physical barrier between East and West Austin, and perpetuating racial and economic divisions for decades. The City of Austin first established a racial barrier along East Avenue by adopting its 1928 land use plan that segregated the city for years. Austin has long since removed the segregationist language from its legal code and land use plan, but the physical barrier has remained. The redesign and construction of the new I-35 Capital Express has a role to play in rectifying this historical inequity for Central Texas. The Austin Transportation Department seeks to address this historical barrier in our approach to partnering with TxDOT. 

The reconstruction of I-35 is one of the most important mobility projects for the Central Texas region, and critically important for all partners to get right for the future of the area. Along with the major transit investment our community is making with Capital Metro, this project will have a long-term footprint on the fabric of our community. 

Not only is this project important for freight movement and automobile users, the I-35 corridor is also important for transit riders. Capital Metro currently operates MetroExpress, MetroFlyer, and UT Shuttle bus routes along the corridor and has plans to expand transit service on I-35 as part of the Project Connect system plan. That proposed expansion includes new service opportunities to outlying Austin neighborhoods and suburban cities, new park-and-rides, new prioritization for transit on future managed/HOV lanes, and preferential transit access ramps. All of these new transit enhancements are dependent on the design of the future I-35. 

The City of Austin has been a partner with TxDOT since the inception of the reconstruction program and was an early funder for design and environmental efforts.  We have consistently represented our residents in seeking an improved I-35 that prioritizes the movement of people and goods through the corridor, improves the efficiency in accessing the downtown and central Austin street grid system, improves east-west connectivity, improves safety and promotes non-motorized bicycle and pedestrian activities. 

Capital Express projects


Project limits: US 290 E to SH 45 N

Estimated construction cost: $400 million 

Estimated construction start: 2022


Project limits: SH 71/Ben White Blvd. to US 290 E

Estimated construction cost: $4.9 billion

Estimated construction start: 2025


Project limits: SH 45 SE to SH 71/Ben White Blvd. 

Estimated construction cost: $300 million

Estimated construction start: 2022

Why I-35 needs to be replaced

  • Mobility: The existing I-35 facility is one of the oldest freeways in Texas—it has outlived its functional lifespan and needs to be replaced to continue its essential mobility function. Existing I-35 operations also create local grid congestion. Improved access to our primary employment destinations is needed to reduce impacts on local street traffic congestion.
  • Safety: More than 40 pedestrians and bicyclists were killed trying to cross I-35 main lanes and frontage roads in Austin, and an additional 20+ were seriously injured, from June 2016 to May 2021, according to the City’s Vision Zero analysis. In addition, more than 40 motorists have been killed and an additional 350+ have been seriously injured in vehicle crashes on I-35 facilities.1 These figures do not include additional cyclists and pedestrians killed on sidewalks and cross streets along I-35 and thousands of crashes that resulted in minor injuries. I-35 needs to be reconstructed with modern design and safety features to reduce fatalities and serious injuries. 
  • East-West Access: I-35 has long acted as a physical barrier between East and Central/West Austin. The facility has separated communities of color from access to employment, educational opportunities, entertainment, and services located in Central Austin. The new highway design must facilitate east-west access. TxDOT has proposed to remove the barriers by lowering the main travel lanes below street level, allowing the City of Austin and partners to create a cap to bridges the East-West divide. 

1 - Source: City of Austin Vision Zero crash statistics from 2016-2021 on the I-35 corridor

City of Austin Engagement
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The City of Austin's role

In a 2010 bond election, Austin residents authorized a $1 million engineering analysis to examine how to improve I-35 within its existing footprint. The City of Austin has since worked with TxDOT and other transportation agencies to identify short-, mid-, and long-term strategies to improve I-35 through the metropolitan area. As TxDOT embarks on the long-term construction projects, estimated to total $5.6 billion, the City of Austin is a Participating Agency in TxDOT’s National Environmental Policy Act (NEPA) study that is required of federally funded projects.  

The City of Austin departments have consolidated our comments on TxDOT's scoping materials and environmental publications to date for the Capital Express Central project, and the Austin Transportation Department commented on TxDOT’s public hearings for the North and South I-35 environmental assessment processes. Detailed comments for those projects can be found here:

City of Austin Dec. 29 letter responding to Capital Express Central project (12/29/2020) 

City of Austin Dec. 29 department comments on Capital Express Central project (12/29/2020)

Austin City Council resolution to TxDOT (3/25/2021)  

City of Austin April 7 department comments on Capital Express Central project (4/7/2021) 

City of Austin April 9 letter responding to Capital Express Central project (4/9/2021)

Austin Transportation Department comments for public hearing on Capital Express South (5/25/2021) 

Austin Transportation Department comments for public hearing on Capital Express North (6/9/2021)

Video: Austin City Council discussion of I-35 (08/31/2021)

Austin Transportation presentation: City Council work session (08/31/2021)

The City of Austin's goals

Austin City Council passed a resolution to TxDOT on March 25, 2021 supporting the goals provided by City staff, including: 

  • The I-35 rebuild should increase the safety for people by designing frontage roads to urban arterial standards and speeds. 

  • The I-35 replacement should seek to maximize the safe movement of people, goods, and services on the corridor.

  • The I-35 replacement should seek to maximize east-west access across the facility for all modes of travel.

  • The I-35 replacement should seek to operate within the existing footprint wherever possible. 

  • New capacity should be managed to provide prioritization of transit and higher occupancy vehicles to minimize the increase in vehicle miles of travel (VMT).

  • Any additional lanes within the existing footprint should specifically address access and egress movements, merging movements, or address documented bottlenecks and/or safety issues caused by geometric features. 

  • Avoid, minimize and mitigate negative environmental impacts of freeway reconstruction.  

  • Assure a thorough public process that meets both the spirit and letter of the National Environmental Policy Act (NEPA). 

Cap & Stitch
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TxDOT is proposing a major reconstruction of I-35 through Austin, and through their effort, the city has a unique opportunity to address longstanding equity and mobility issues regarding the I-35 corridor. In coordination with TxDOT's federally regulated planning process, the city can drive cap and stitch development, funding and implementation. If approved, TxDOT's planned improvements will include the structural infrastructure to hold up the city's cap and stitch plan. Working together with the community, our agencies can bring solutions to a long-discussed problem.

As TxDOT considers lowering the central portion of I-35 through downtown Austin, the opportunity exists for the City of Austin to create "caps," or decks covering the highway that can reclaim that property as public space, and "stitches," or wide bridges that would add enhanced east-west connections across I-35.

The Downtown Austin Alliance (DAA) engaged a panel of experts from the Urban Land Institute in 2020 to provide recommendations on those spaces. You can read more about their work here.

Resources banner

My35Capex: TxDOT's I-35 North, Central, and South projects website 

A Citizen’s Guide to NEPA: The Council on Environmental Quality (CEQ) January 2021 

Our Future 35: A collaboration between the Downtown Austin Alliance and a diverse coalition of Austin leaders  

Get Involved
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TxDOT is providing multiple methods for residents to give their feedback.  

Visit: TxDOT's I-35 website to learn more about the Central, North and South Capital Express projects.

Visit: The I-35 Capital Express Central project virtual public meeting and submit your feedback from Tuesday, Aug. 10, through Friday, Sept. 24, 2021. The purpose of this virtual public meeting is to provide an opportunity for the public to review and comment on:

  • Results of the alternatives evaluation
  • Findings from an independent study of the community alternatives
  • Proposed build alternative layouts

Attend: Review the designs in person. You can stop by the Austin Central Library, 710 W. Cesar Chavez St., and the Austin Public Library Carver Branch, 1161 Angelina St., anytime the library branches are open. 

Email: TxDOT comments or questions at 

Call: TxDOT with a comment or question at 512-366-3229. 

Ask: Request a presentation to your civic organization or neighborhood association. Call 512-832-7357 or email 

Join: TxDOT's mailing list for program updates at 

Subscribe: Sign up for the Austin Mobility Newsletter to receive additional local updates.