Recent History of the I-35 Project

I-35 is an interstate highway running North-South from Laredo, Texas to Duluth, Minnesota. It runs through Austin, TX between downtown on the West side of the highway and East Austin on the East side. I-35 is a federal interstate which is operated by the Texas Department of Transportation (TxDOT).

In September 2020, TxDOT began implementing a proposal to expand the portion of I-35 in Central Texas. They are undergoing a three-part project:

  • I-35 Capital Express North, from SH 45 in the North to US 290 East in the South. 
  • I-35 Capital Express Central, from US 290 East in the North to SH 71/Ben White Boulevard in the South, with additional flyovers at I-35 and US 290 East.
  • I-35 Capital Express South, from SH 71/Ben White Boulevard in the North to SH 45 Southeast in the South.

I-35 Capital Express Central proposes to expand the portion of I-35 that runs through Austin. 

Map of project area for I-35 Cap Ex Central. Source.

I-35, as it runs through Central Austin today, is an average of 12 lanes wide, including main travel lanes and access lanes. TxDOT’s proposal for this segment of the highway is to add two non-tolled managed lanes (essentially non-tolled HOV or “carpool” lanes) in each direction, raising the total number of lanes in Central Austin to 20.

TxDOT is undergoing the federally mandated NEPA process for this project. NEPA, the National Environmental Policy Act, is a federal law passed in 1970. The purpose of the law is to force major infrastructure projects receiving federal funding to evaluate their impacts on the surrounding environment before construction can begin. This includes analysis of environmental and cultural impacts of project construction and maintenance. 

Texas is one of seven “assignment” states under NEPA. Under normal conditions, the Federal Highway Administration (FHWA) is the agency in charge of NEPA and signs off on environmental analyses of proposed projects. However, in the “assignment” states, the state government is the agency in charge of NEPA instead. In Texas, the FHWA ceded their authority to certify projects under NEPA to the state government by signing a Memorandum of Understanding (MOU). This means that for interstate highways like I-35, which are operated by the state but receive federal funding, TxDOT is the agency in charge of proposing the project, performing the environmental analysis required by NEPA, and signing off on the project so it can be constructed. 

NEPA requires the agency instituting a major infrastructure project to evaluate the effects of several proposed project “alternatives” (versions of the project that could be constructed) against a No Build scenario (a control). NEPA also requires this analysis to be made public, and for the agency to hold several rounds of Public Engagement, where the community affected by the project has an opportunity to view project materials and learn about its predicted effects. The community then provides feedback during a set period of a minimum of 30 days. These feedback comments are legally mandated to be part of the public record, and can be requested by a member of the public under a Freedom of Information Act (FOIA) request. 

TxDOT is undergoing the most thorough level of environmental analysis under NEPA, which is called an Environmental Impact Statement (EIS). EISs are required for major infrastructure projects. Smaller projects can pursue an Environmental Assessment (EA) instead, which requires less analysis and less public engagement than an EIS. More information about NEPA and its requirements can be found in the “Citizen’s Guide to the National Environmental Policy Act; Having Your Voice Heard.” 

The timeline of NEPA analyses. Source.
TxDOT’s project timeline for the EIS process. Source.

The Scoping period for I-35 Central (which includes the “Range of Alternatives,” “Evaluation Criteria,” and “Refined Range of Alternatives” periods in diagram above) began in November 2020. TxDOT held a 30-day Virtual Public Meeting, which included an introduction to the project, a statement of the project’s Purpose and Need, limited information about the project, and an opportunity to submit comments. The information provided at this time was very limited and did not include any specific plans or schematics; a few sketches were shown without measurements and with the caveat that all designs were subject to change. The project included a No Build scenario and three very similar Project Alternatives, each of which proposed to widen I-35 Central to 20 lanes. This first period of public engagement began November 12, 2020 and ended December 31, 2020. It was planned to be only 30 days, but following repeated calls from the public and elected officials to extend the period and allow further time for community involvement, especially over the holiday season, TxDOT extended the period to 45 days.

I-35 Cap Ex Project Fact Sheet shared during the first round of public engagement. Source

Community organizations, individuals, and the City of Austin provided feedback to TxDOT during the first round of public engagement. Several of those letters, including Reconnect Austin’s official feedback, can be found here.

The second Virtual Public Meeting held during Scoping lasted from March 11, 2021 to April 9, 2021. In this meeting, TxDOT shared slightly more detailed project plans, an updated Purpose & Need statement, and responses to comments received during the first meeting in late 2020. The Purpose & Need statement was revised to make safety the project’s top stated priority, in response to hundreds of community requests. TxDOT shared a report of comments received during the first Scoping meeting, which included grouping comments into “themes” and then responding to those themes as a whole. Reconnect Austin’s response to this practice can be found in our official response letter to TxDOT, dated April 2021.

Project information shared during the second round of public engagement. Source.
TxDOT’s revised Purpose and Need statement released during the second round of public engagement. Source.

Community organizations, individuals, and elected officials again provided official feedback during this second period of public engagement. A collection of those letters can be found here.

The third and final Virtual Public Meeting held during Scoping began August 10, 2021. TxDOT held an in person event at Huston-Tillotson University where they shared project updates as well as project schematics for the first time. They simultaneously debuted a Virtual Public Meeting website in the same format as the previous two virtual meetings, which contained the same information and graphics shared in person. At this meeting, TxDOT shared that they were not moving forward with Alternative 1 of the I-35 Cap Ex Central project. Alt 1 utilized tunneled lanes and would have been narrower than Alt 2 and 3. It therefore required less land acquisition from properties neighboring I-35. It was discarded due to construction costs and concerns about emergency vehicle access to the tunneled lanes. Having discarded Alt 1, TxDOT claimed they would move forward with Alternatives 2 and 3, which were shown to be exceedingly similar except for a few East-West crossings. Project schematics were shared publicly for the first time.

Example of project schematic for Alt 2 shown during the third round of public engagement. Source.
Example of project schematic and section for Alt 3 shown during the third round of public engagement. Source.

Also on August 10, 2021 TxDOT shared its findings from a report they commissioned of the Texas A&M Transportation Institute (TTI). This institute receives its funding from TxDOT and frequently publishes research and analysis at the agency’s request. Earlier in the summer of 2021, TxDOT had commissioned TTI to write a Feasibility Report on Reconnect Austin and ReThink35, a proposal which would see I-35 completely removed through Austin and replaced with a multimodal urban boulevard. TTI was tasked with analyzing both projects and comparing them to TxDOT’s proposal for I-35 Central. The report found that neither Reconnect Austin nor ReThink35 were feasible in Austin due to concerns over traffic congestion being pushed onto city streets and lack of secured funding. TxDOT has refused to pay for caps over I-35 or supports for caps, and the TTI report noted that funding the caps could be a primary barrier to construction of either proposal. 

The TTI report had some primary issues. The agency had only 30 days to do a complete analysis of both proposals and to compare each to TxDOT’s proposal. The report’s financial analysis did not include any discussion of value generation or return on investment, which is a key aspect of Reconnect Austin’s proposal for funding. Lastly, the report is based on flawed traffic modeling from the CAMPO 2040 Growth Forecasts, which assumes that in a No Build scenario traffic congestion would increase so much on I-35 that by 2040, commuting between Austin and Round Rock would take several hours. This ignores everything we know about human behavior, which indicates that congestion will never reach a level so inconvenient to drivers. More about the flawed modeling behind the TTI Feasibility Report, which has also been used to justify the I-35 Capital Express Central project itself, can be found here

The third Public Meeting held under Scoping lasted from August 10, 2021 to September 24, 2021. During this 45-day public input period, Austin community members, elected officials, and several advocacy groups spoke out publicly against the project in its current configuration. The primary issue most fought back on was the land acquisition proposed by TxDOT to expand I-35. Widening the highway would require acquisition of over 140 properties along I-35. These included homes and local businesses. Residents from the Cherrywood neighborhood and small business owners along I-35, whose properties were to be taken by TxDOT if the expansion should go through, organized to speak out against this project. Reconnect Austin worked to raise awareness about the project and the proposed land acquisition, and met with residents and business owners who would be displaced. Reconnect Austin worked with ReThink35 to organize a press conference on September 1, 2021 to allow community members, advocacy organizations, and elected officials to speak out about the project and voice their concerns. More information, video footage and media coverage of the press conference can be found here.

Reconnect Austin, along with a number of community organizations, the City of Austin, and Travis County Commissioners Court provided feedback to TxDOT expressing concerns about the project and its effects on Austin. Those letters can be found here.

When TxDOT completed its third round of public engagement in September 2020, it ended the Scoping phase of the EIS process and began writing the Draft Environmental Impact Statement. This period of the EIS process does not mandate any public engagement, and TxDOT has been working internally on writing the DEIS and updating the project alternatives with respect to community feedback. Over the course of Scoping, TxDOT received over 9,500 different points of community feedback. These range from detailed letters from elected officials to comments submitted via form on the project website. Reconnect Austin is so grateful to the people of Austin for mobilizing around this project and submitting feedback to TxDOT. This level of public engagement is extremely rare for public infrastructure projects, and reflects a strong community desire for an improved I-35 corridor that serves the people of Austin.

While TxDOT has decided not to consider Reconnect Austin or ReThink35 as official Project Alternatives in their EIS, they are working with the City of Austin to consider some capping over I-35 Central. The City of Austin is operating its I-35 Cap & Stitch project, which is in partnership with but separate from TxDOT’s I-35 Cap Ex Central project. The City proposes to build a few separate caps (lids over I-35) and stitches (extra-wide bridges over I-35). This project was first considered by the Urban Land Institute at the request of the Downtown Austin Alliance. Their Advisory Services Panel came to Austin in February 2020 to provide recommendations on the portion of I-35 that runs through downtown. Reconnect Austin was one of several groups that consulted with the ULI Panel during this time. The Panel’s report can be found here.

The proposed caps and stitches would be funded by the City, but certified under TxDOT’s NEPA process for I-35. The premise of the project is that TxDOT will widen I-35 to add 2 non-tolled managed lanes in each direction, but design it in a way that the City can build caps over the newly depressed highway and reconnect the East and West sides of the city at the surface level. 

The City of Austin debuted a Cap & Stitch website on December 15, 2021. The website includes a video explaining the possible locations for caps and stitches between Cesar Chavez St and Airport Blvd, and a survey for community members to provide feedback on cap/stitch locations, design and amenities. Caps may be used for parkland, public buildings, private development, public art, etc. The City of Austin will conduct public engagement in 2022 and 2023 to gather information on what should be built on the caps and stitches. They will design the caps to a certain point, at which TxDOT and TxDOT’s consultants will finalize the design and evaluate it under the same NEPA process as the rest of I-35 Central. TxDOT will manage construction of these caps and stitches, though the City of Austin is responsible for funding them.

Example of potential cap location from Cesar Chavez St. to 8th St. in downtown Austin. Cap shown in green. Source.
Example of potential stitch location at 38½ St. Stitch shown in blue. Source.

In January 2022, TxDOT released a statement that they had listened to the over 9,500 comments received during Scoping and had made changes to Alt 3 of the project. An internal memo from City of Austin staff to Mayor Adler and City Council outlined some of the possible changes, including a configuration of the frontage roads as an urban boulevard and potential locations for future caps and stitches in partnership with the City of Austin. The memo gained media attention

Those changes debuted at a public meeting held by TxDOT on January 25, 2022 in the form of Modified Alternative 3 (Mod Alt 3). Mod Alt 3 has the main lanes of I-35 depressed and the surface-level frontage roads pulled to one side of the highway, running in parallel as an “urban boulevard” through downtown Austin. Next to the “boulevard” is open space above the main lanes of the highway which could be capped, though decisions regarding capping are being left to the City of Austin. While Mod Alt 3 does not represent the entirety of Reconnect Austin’s vision for I-35, it does show great strides towards a better project, and we are encouraged by the design possibilities for the “boulevard.” With slow design speeds, protected bike and pedestrian infrastructure, street trees and furniture, and so forth, the combined frontage roads could start to feel like a regular city street. The potential for more caps over I-35 next to the boulevard would drastically change how I-35 looks and feels through downtown Austin. This boulevard and cap treatment is also being considered where I-35 crosses UT campus, and could provide valuable new land to the university as well as provide safe crossings for students and employees.

Example of the combined frontage road (“urban boulevard”) configuration at Dean Keeton St from Modified Alternative 3. Potential cap is shown in green. Source.
Example of the combined frontage road (“urban boulevard”) configuration from Cesar Chavez St to 8th St from Modified Alternative 3. Potential cap is shown in green. Source.

TxDOT released its Draft Environmental Impact Statement on January 5, 2023. The DEIS has a 60-day public comment period from January 5 to March 7, 2023. Any comments received by TxDOT within this comment period will go onto the public record and must be evaluated by TxDOT.

With the release of the DEIS, TxDOT has demonstrated their intent to move forward with Modified Alternative 3, which provides opportunities for caps and stitches given that the City of Austin provides funding for their construction, operations, and maintenance.

The entire DEIS can be read online at The entire document, complete with 23 appendices, runs approximately 7,000 pages. For a quick overview of the DEIS and its impacts on this project, check out great coverage from KUT and the Austin Politics Newsletter:

KUT: TxDOT Narrows Options for Widening I-35 Through Austin

Austin Politics Newsletter: TxDOT Releases its Preferred I-35 Expansion Plan

KUT: I-35 Questions and Answers

We encourage anyone interested in this project to submit their feedback to TxDOT regarding Modified Alternative 3 and the proposed project. Ideal feedback is submitted during the DEIS public comment period Jan 5 – March 7, 2023, but feedback at any point in this project is crucial and helps advocate for a better I-35 and a better future for Austin. Comments may be submitted to TxDOT via any of the following methods:

  • EMAIL:
  • MAIL: I-35 Capital Express Central Project Team, 1608 W. 6th Street, Austin, TX 78703
  • ONLINE: or

As this project updates, Reconnect Austin will continue to stay involved and advocate for a better I-35 corridor through Austin. Please follow us on Twitter and Facebook @ReconnectAustin. We share project updates as well as information about other freeway fights around Texas and the US. Media inquiries should be sent to

All of TxDOT’s project materials, including past held meetings and materials shared during Scoping, can be found here

More information about Reconnect Austin’s proposal to bury and cap I-35 through central Austin can be found here.