The I-35 Caps Depend on Partners

There is a version of the I-35 cap story that still circulates in this market. It goes like this: a single deadline in November 2026 decides whether roughly 14 acres of new deck gets built over downtown Austin, and if the City misses it the next chance is 2043.

That framing is wrong in three specific ways, and the corrected version is more useful than the dramatic one.

The City of Austin put its own answer in writing on March 24, 2026, in a Council work session backup titled "I-35 Cap and Stitch, Cap Decks, Staff Recommendations," File ID 26-1392 (City of Austin). Everything below that is attributed to "the March 2026 staff presentation" comes from that document. It is the primary source, it is public, and it is more specific than the coverage built on top of it.

What the City actually paid for

On May 22, 2025, Council adopted Resolution No. 20250522-042. It authorised $104 million and an Advanced Funding Agreement with TxDOT for Roadway Elements, Phase 1, which the resolution describes as "preserving the opportunity for future cap decks" at five locations:

• Cesar Chavez Street to 4th Street
• 4th Street to 7th Street
• 11th Street to 12th Street
• Two 300-foot stitches from 41st Street to the Red Line

Roadway elements are the structure underneath. Columns, foundations, tunnel provisions, the lowered-highway geometry that leaves a deck possible later. They have to be built while the highway is being built because retrofitting them is not practical. They are not the deck, and they are not a park.

That is the whole commitment. $104 million of support structure, plus $15.4 million the presentation says Council has already committed for 100% design. Nothing for the decks.

The five locations total 13.98 acres in the City's own table: 10.82 acres across the three downtown caps and 3.16 acres across the two northern stitches. That is where the "roughly 14 acres" figure comes from, and it is acreage of potential deck, not of funded deck.

One detail worth knowing if you are tracking the money. The Phase 1 roadway elements are now estimated at $86 million against the $104 million authorised, because the northern stitch roadway elements came in at about $8.4 million. With the 20% contingency already inside the $104 million, the presentation says the City has $32 million of the $104 million available to absorb cost increases as engineering progresses. That is a buffer on the foundations. It is not seed money for decks.

The three dates people are conflating

This is the part the circulating version gets wrong. There is not one deadline. There are three separate milestones, and they ask for three different things. The March 2026 staff presentation lays them out on a single slide headed "Upcoming TxDOT Cap Deck Milestones."

May 2026 was which locations. November 2026 is the money. They are not the same gate, and the May one is the one that came first.

The May 2026 date exists because TxDOT advanced it. Community Impact reported on December 12, 2025 that TxDOT moved the City's cap deck funding-commitment deadline forward from November 2026 so it could start scope and budget negotiations with its consultant sooner, which meant the City would be deciding at roughly 30% design rather than the 60% it had planned on, and that "the city's risk profile has increased" (Community Impact, December 12, 2025).

So the original November 2026 date did not disappear. It split.

What staff recommended, and the sentence that matters

The March 2026 presentation carries a slide headed "Staff Recommendation on Cap Decks." It says two things:

Continue with vertical elements/future proofing only.

City invites community leaders to assist in identifying partners for cap decks development that do not require any additional City funding.

Elsewhere in the same deck, responding to Council's own Resolution No. 20250522-105, staff put it in four words: "Staff does not recommend City-funded caps."

Then the Next Steps slide, which is the sentence to read twice:

Inform TxDOT of City response on location commitment for cap decks in initial bid package by May 2026. Staff recommendation, no City funding for cap decks in initial bid package, Council does not need to take any formal action.

Read that mechanically. The recommended outcome required no vote. There was no dramatic decision to lose. The path staff recommended was the one that happens if nobody does anything, and the deadline for it was four months ago.

That is the correction. This was never a cliff-edge vote in November. It was a staff recommendation in March that defaults through unless somebody actively overrides it.

Why the money is not there

The presentation is unusually candid about this, and the reasons are structural rather than political.

The federal grant is gone. Austin was told on August 6, 2025 that it would not receive the $105 million Neighborhood Access and Equity grant for the project. The city memo attributed the loss to the elimination of unobligated NAE funds "as part of H.R. 1, One Big Beautiful Bill" (Spectrum News 1, August 8, 2025). Staff now advise that "federal funding should not be assumed as a primary cap deck funding source in the near term," and note that the federal surface transportation law expires September 30, 2026 with an uncertain reauthorisation.

The number is $604 million. Cost estimates updated January 29, 2026 put Phase 2 cap decks at $346 million, design at $25 million, and Phase 3 to 5 amenities at $258 million, for a construction total of $604 million, plus about $9 million a year in ongoing structure maintenance. The 11th to 12th Street deck alone was revised from $53 million to $86 million, a 62% increase, after TxDOT design changes to accommodate two-story buildings.

Attach the accuracy caveat the City attaches. Those estimates sit at the 30% to 60% design band, which the presentation marks as a -33% to +50% range, in 2025 dollars, on original bid conditions, and excluding utility infrastructure.

Local funding sources are ruled out one by one. The presentation walks the list and disqualifies most of it. Street impact fees are ineligible. Temporary right-of-way fees are fully allocated. Five years of downtown parking district revenue is under $7 million. Hotel occupancy tax is committed to Convention Center redevelopment for the next 30 years. Certificates of obligation and voter-approved general obligation bonds both carry "debt capacity concerns." The State Infrastructure Bank loan is already maxed at $41 million.

Value capture does not close it either. Tax increment west of I-35 is already allocated to the Waller Creek TIRZ, and east of it to Homestead Preservation District 1. Capital View Corridors cap the density, and therefore the increment, next to the downtown cap locations. The City had CBRE value two sites it could sell, at roughly $48.5 million and $11 million, and concluded that monetisation "falls far short of the value required."

Nobody else has put money in. The presentation benchmarks six comparable deck-park projects and finds philanthropy covered roughly half or more of construction in four of them, and that city funding was under 25% of total cost in every one. The bar for Austin Caps and Stitches on that same chart shows city money and nothing else.

The fallback is not 2043

This is the second thing the circulating version gets wrong, and getting it wrong changes how you price the corridor.

If the caps are not in the initial bid package, the City's own recommended process is not "wait until 2043." It is this, in order, from the slide headed "Recommended Process for Developing Cap Decks":

1. City enables caps by funding roadway elements. Done, $104 million, May 2025.
2. Identify funding partners who will develop cap decks.
3. City or funding partner signs an Air Rights Agreement with TxDOT.
4. TxDOT executes a change order for the design and construction of cap decks.
5. Funding partner builds on the caps.

The change-order window is 2030 to 2032, and the cost of using it is stated in a footnote: cap decks added by change order or separate contract after TxDOT's letting "may increase deck costs by 35% to 100% or more."

2043 is the fallback to the fallback. It is what happens if the change-order window also closes, because the presentation says full project completion around 2033 "begins 10-year moratorium for future cap decks."

So the honest shape of this is not a binary that expires in November. It is a narrowing sequence of progressively more expensive doors, and the cheapest one has already been declined on staff advice.

Note also that the moratorium is the City characterising TxDOT's position. We did not find a TxDOT-published document stating it, so attribute it to the March 2026 City presentation rather than to TxDOT directly.

What is not known

Being straight about the edges is more useful than filling them in.

• We could not find any reporting on this dated after early June 2026. Our searches on September 11, 2026 returned nothing from July, August or September. So the position described here is verified through the March 2026 presentation and the coverage around the May and June Council cycle, and not beyond it. Something may have changed that we cannot see.
• We do not know what the City actually told TxDOT in May 2026, or whether it sent anything at all. Staff recommended a response that required no Council action, which means there may be no resolution to look up. The document that would settle it is the City's written location-commitment response to TxDOT, or its absence.
• We cannot confirm the Advanced Funding Agreement has been executed. As of March 24, 2026 it was still listed under Next Steps as something to "negotiate and execute," including the payment schedule. An authorised agreement and an executed agreement are different things.
• We could not pin the approval date for the $15.4 million in design money. The March 2026 presentation states the commitment as a fact in a footnote. We could not match it to a specific Council action, and the reporting we found on design funding does not reconcile cleanly. Pull the Council record before relying on that figure.
• The scaled-back single-cap proposal Mayor Watson floated in May 2026 and then withdrew is reported with conflicting numbers and conflicting locations. We saw roughly $50 million, $49.8 million and $41.3 million, and both Palm Park and Third Street named as the site. We are not going to pick one. If the details of that proposal matter to you, pull the posted agenda item rather than any write-up, and note there was a separate Watson downsizing proposal in May 2025 that is easy to confuse with it.
• Whether Council commits a funding source by November 2026 is genuinely undecided. That is the next real gate. What would settle it is a resolution or ordinance on a November 2026 Council agenda, and the executed TxDOT air rights or multi-use agreement that the presentation lists as pending.

What it means if you are underwriting in the corridor

Three reads, in order of how much money they are worth.

1. Stop modelling the caps as a coin flip and start modelling them as unfunded. The base case is now the City's own stated position: support structures built, decks not funded, partners sought. A pro forma that treats the deck as roughly even odds is more optimistic than the City is about its own project. If you want the upside case in the model, price it as a partner-funded change order landing between 2030 and 2032 at a 35% to 100% premium on deck cost, because that is the mechanism the City has actually described.

2. The northern stitches are still the under-priced half, and now for a different reason. They are small. The roadway elements for both came in at about $8.4 million, the two decks at about $69 million in the January 2026 estimate, against roughly $250 million for the three downtown decks. A partner-funded stitch at 41st Street, next to a commuter rail station and the Hancock and Hyde Park land, is a materially smaller cheque than a downtown cap. Where a partnership actually closes first, size is the reason.

3. Adjacent construction is the near-term fact, and it is not conditional on any of this. TxDOT's phasing puts the Downtown and University segments of Capital Express Central at 2027 to 2033 regardless of what happens to the decks. If you hold frontage in that stretch, you are pricing roughly six years of adjacent heavy construction that starts next year, with or without a park at the end of it. That is a full development cycle, and it belongs in the hold period now rather than in a revision later.

The broader entitlement picture in this region has moved in the opposite direction over the same period, which is part of why this one is worth the care. We wrote about that in SB 840, one year in, and the screen we run on a corridor parcel is in the pre-entitlement checklist.

If you have a parcel or a submarket in this corridor and want a second read on the unfunded case rather than the rendering, get in touch.

This post is general information about infrastructure and land use policy in Central Texas. It is not legal, engineering or investment advice, and it is not a representation about any specific parcel. Figures and dates are attributed to the source and the date that source published them. Infrastructure timelines, cost estimates and funding decisions all change, and the most recent coverage we could find on this topic predates July 2026. Verify every date, figure and funding status against the issuing agency or the Council record before relying on it.