The City of Austin has unveiled its final vision of what Interstate 35 could look like after parks are installed on top of the highway — an ambitious and expensive project made possible by the Texas Department of Transportation's (TxDOT) once-in-a-generation expansion of the biggest road in Central Texas.
TxDOT will lower the main lanes of I-35 up to 40 feet beneath ground level from Holly Street to Airport Boulevard. The city wants to install almost 30 acres of deck parks over those sunken lanes, much like Klyde Warren Park in Dallas — but more than five times larger. That doesn't even include 17 acres of deck parks UT Austin plans to build over the highway.
"We're really excited about the vision plan, because it really is going to set the tone for how we move forward," said Brianna Frey, an urban planner overseeing the city's deck park project dubbed Our Future 35.
To clarify some terminology, the city refers to these highway lids as "caps and stitches." Caps are more than 300 feet wide, and require advanced ventilation and fire suppression technology for the lanes below. Stitches are essentially caps that are less than 300 feet wide and don't require as much equipment.
While the first cap could open as soon as 2032, a child born today would have graduated college by the time the plans depicted below are fully constructed. But the project would be done in phases. Austinites would see bare-bones caps grow into parks with simple landscaping and then evolve as more amenities and buildings are added over several years.
One big question: Who will pay for this? TxDOT says it's not allowed to use its billions in annual funding to build the caps or the things that will go on top of them, so the city has to foot the bill. The same goes for UT Austin and the caps it's planning from 15th Street to Dean Keeton.
The price tag for the city is estimated to top $800 million, not accounting for inflation. But with a construction timeline stretching as far as 2050, the real cost remains unknown.
The money will come from a variety of sources, possibly including local property taxes. A nine-figure bond election is expected in November 2025.
The city has already scored a $105 million grant from the federal government to build the first cap from Cesar Chavez to Fourth Street, including many — but not all — of the amenities on top. Another $309 million in loans and grants are being sought.
Another question: How will the caps be managed? Austin is strongly considering the approach of other cities like Dallas, where private entities operate the park and hire security and custodial staff to create an environment where families feel safe. But the highly-controlled approach has faced criticism in cities like Dallas where people living on the street are pushed out, organized sports are banned, feeding birds is prohibited, and no one is allowed to ride bicycles, scooters or skateboards.
Notably absent from the plans are the stitches planned at 51st and 32nd Streets. These appeared in earlier designs but were removed from this final vision going to the city council next month.
"With some feedback from community members that longer caps are more of a community benefit than the shorter stitches, the city decided to focus efforts on the cap opportunities rather than the stitches," said Jack Flagler, a spokesperson for Austin's Transportation and Public Works Department.
So let's tour the latest version of this project to transform the landscape of Central Austin. If you want to zoom into the site plans in more detail, you can download the 346 MB PDF we obtained from the city. (Spanish version here.)
Holly Street stitch (estimated cost $23 million)
A stitch jutting out south of the Holly Street bridge would be the southernmost park over the highway.
The Holly Stitch would have a playground, space for food trucks, a dog park, trees, shade structures and a 1,700-square-foot building with restrooms and storage. The building could hold maintenance gear or equipment used by people putting on events in the park.
The orange dot represents possible public artwork.
The East Avenue Trail, shown in yellow, is conceptual right now. The path would connect all the caps and stitches, potentially traveling through UT Austin's caps. East Avenue was the name of the street that served as a racial segregation line in Austin for decades. The division became even more entrenched when East Avenue was chosen in the 1950s as the route for I-35.
TxDOT is planning to build sidewalks up to 12 feet wide on both sides of the expanded highway, which could form part of the trail. But wherever possible, the city wants to bring that sidewalk onto its caps so the East Avenue Trail could be up to 20 feet wide, possibly with separate lanes for cyclists and pedestrians.
The East Avenue Trail could travel down Rainey Street and connect to a new trailhead that the city and The Trail Conservancy are building at Lady Bird Lake.
Cesar Chavez to Fourth Street cap (estimated cost $179 million)
The cap from Cesar Chavez to Fourth Street would be 5.3 acres, about the size of Dallas' downtown highway park.
This cap is right next to Sir Swante Palm Park, which is on track to undergo a major renovation with the groundbreaking planned for 2026. The city wants to complement the child-focused vision of Palm Park by offering recreation on the highway cap for teenagers and young adults. Sports courts on the deck park could be used for basketball or tennis.
This cap includes a possible extension of the park over the highway just south of Cesar Chavez with canopies and "cooling stations." Those stations would be shade structures to start but might one day include misters or fans.
At the corner of Cesar Chavez and the northbound frontage road (I-35's frontage roads will run side-by-side from Cesar Chavez Street to Dean Keeton Street) would be a 16,000-square-foot building up to two stories tall. The city doesn't know who would occupy the building, but imagines a possible food market with a variety of stands inside. People could buy prepared meals and eat them in the covered dining space next door.
The "hammock grove" would be either a bring-your-own-hammock area to hang beneath the shade of trees, or the city could install public swinging chairs.
Third Street would be the spine of this cap, with the pedestrian crossing over the interstate imagined as a tree-lined promenade.
North of Third Street, the cap would have a "rock scramble" — basically, large rocks for people to climb around on.
A pavilion at the north end of the cap would serve a variety of purposes, potentially hosting performances in front of the lawn with a capacity of 2,500 people. However, the lawn would be sloped toward Third Street in part to help with drainage challenges.
Capital Metro's Red Line will run across I-35 at Fourth Street next to the Red Line Parkway, a project to build a 32-mile linear park next to CapMetro's train tracks from downtown Austin to Leander.
Plans call for installing a "bike hub" at the intersection of the Red Line Parkway and East Avenue Trail. The bike hub could host a vendor doing bike rentals or simply provide bike parking.
Fourth to Seventh Street cap (estimated cost $126 million)
The cap closest to Austin's downtown nightlife would build off the buzz of Sixth Street and nearby Red River with a focus on entertainment. The deck park would have more performance spaces and buildings than any other cap.
The exact sizes and uses of the building would be determined in the future, and the public would have some say.
But the cap could be a money-maker for the city with lots of space for private or ticketed events, generating income for companies that could lease the areas. The plan includes eight buildings, each up to two stories tall, ranging in size from 3,200 square feet to 20,000 square feet.
The proposed skating area at the south end of the cap could have ramps and hills. People suggested the idea during the public comment period, but the skating area is not set in stone.
"We'll see once we get to design if it stays or if it bounces to one of these other caps," Frey said.
11th to 12th Street cap (estimated cost $71 million)
Almost a century ago, Austin's city leaders approved a plan to push Black residents within a six-square-mile area to maintain racial segregation. The historical division was hardened when East Avenue, the segregation line, was made into I-35.
Decades later, this historically Black neighborhood has become known as the African American Cultural Heritage District. One of the most important areas in the district is East 11th Street, which would feed directly into this new cap bridging the widened interstate.
The biggest feature of this highway park is a two-story building for community events. The structure would probably be owned by the city and leased out to an organization. The center of cap would have an outdoor area with a pavilion to create shade.
The footprint of the building and civic space from above almost looks like a cowboy boot.
"Our community partners were really wanting this to be more civic oriented," Frey said. "They really wanted to create some of that lost space for community gatherings."
A second building housing a small business incubator would be constructed at 11th Street and the I-35 frontage roads. A rooftop plaza would be on top.
38 1/2 to 41st Street (estimated cost $178 million)
The proposed East Avenue Trail would run through the center of this cap, which would have a focus on gardens with native landscaping.
Three buildings — each being one to two stories tall and ranging in size from 9,000 square feet to 23,000 square feet — could host restaurants or vendors selling food to eat elsewhere in the park.
An interpretive garden center in the middle of the cap would likely offer information about Central Texas plants and animals.
However, the caps north of 38 1/2 Street present challenges that that don't exist downtown where frontage roads will run next to each other on one side of the highway. With interstate frontage roads on both sides of the parks, pedestrian access is far more restricted. To prevent jaywalking, the city plans to build barriers.
"Maybe fencing's the wrong word because there's a lot of negative connotations with fencing," Frey said, suggesting gates, berms, planter boxes or other structures that would deter people from jaywalking across the frontage roads. "You could really do that without creating a chain link fence."
This limited access also complicates the entry of maintenance vehicles, as well as EMS and fire services.
A pedestrian bridge would provide access to the northbound frontage road.
41st Street to Red Line cap (estimated cost $163 million)
Capital Metro's Red Line will run over the lowered main lanes. Same for the Red Line Trail. TxDOT's plans for the rail bridge required the relocation of famed crystal store Nature's Treasures.
The Red Line stop depicted in this illustration is not part of the transit agency's long-term plan. But city officials got approval from CapMetro to depict a station in the illustration anyway, Frey said.
CapMetro is currently reconsidering its transit network through a long-range process called Transit Plan 2035. So whether this stop ever exists is an open question for now.
One of the main features of this cap is a BMX, rollerblading and skateboarding park. The green circle with a "Plaza" in the middle would be elevated and look down on the skate park.
That plaza would slope down toward the stage and "performance lawn" that has a capacity of 4,500 people.
This cap suffers from the same deficiencies as the one just south of it when it comes to pedestrian access. Multi-lane roads straddle the highway park, and the city and TxDOT don't want people jaywalking. A pedestrian bridge might be constructed linking people to the Hancock Center next door.
"We're imagining if some of these adjacent properties like the Hancock Center redevelop in the long term, how could this 'community hub' — as we're calling it — really create public space that attracts those users to spend some time here and then hop on a train and go where they need to go," Frey said. "That's a little bit of the vision here."
Red Line to Airport Boulevard cap (estimated cost $93 million)
When TxDOT announced in June it was downsizing the Airport Boulevard crossing over I-35, the city realized it would make space for another cap.
The deck park from CapMetro's Red Line to Airport Boulevard would have lots of trees and other barriers to stop pedestrians from crossing mid-block. People would need to get in and out via Airport Boulevard or by crossing the Red Line train tracks from the cap immediately south.
"Some of these caps are going to be somewhat floating in the middle of the highway, and other times, it is going to be a seamless edge-to-edge condition where it might be a little bit more comfortable [to cross the street]," Frey said.
A large sports field with a running track and terraced seating would be the central feature of the cap. Two exercise parks, a dog park with separate space for large and small dogs, a picnic area and small plaza would also be installed.
What's next?
The city council is scheduled to vote November 21 on this so-called "vision plan."
Austin has to prove to TxDOT that it's serious about the capping project. The city must pay the state $19 million by the end of the year to finish engineering designs for the base caps. Local officials must also present TxDOT with a funding plan that shows how the city will pay for everything.
The first highway park expected to open will be the Cesar Chavez to Fourth Street cap. A contractor could be hired by mid-2026 with construction starting later that year. TxDOT could finish its work on the cap by 2032.
Those buildings on the first cap might not be constructed till 2042, depending on how long it takes the city to find occupants and funding.
The full vision detailed in these plans isn't estimated to be complete until sometime around 2050. But with a construction timeline stretching out that long, a lot could change over the next quarter century.
This story was corrected to state that the Red Line Trail would travel from downtown Austin to Leander, not Cedar Park.
