Against a backdrop of chanting protesters, the Texas Department of Transportation held a groundbreaking ceremony Wednesday to mark the start of construction on a $606 million project to expand I-35 from U.S. 290 East to State Highway 45 in Round Rock.
The I-35 Capital Express North Project will add one high-occupancy vehicle lane in each direction along the 8-mile stretch of interstate. Six bridges will be reconstructed. Lanes will be added to bypass intersections. Paths for pedestrians and cyclists will be built.
"I-35 hasn't expanded since the mid-1970s," Tucker Ferguson, Austin district engineer for TxDOT, said. He argued congestion is pushing highway traffic onto local streets. "With the population roughly doubling in the next 20 years, it'll just continue to be choked further and further."

The high-occupancy lanes will be open to vehicles with more than one occupant and to Capital Metro buses using that segment of highway.
Right now, bus routes 1, 243, 300, 323, 325, 337, 392 and 801 cross that section of I-35 north. CapMetro says it could re-evaluate routes to take advantage of the HOV lanes after they open in late 2028.
"It gives us better travel times," Andy Skabowski, CapMetro's chief of operations, said. "It is a better experience for our customers because they get in quicker."
State and local officials gave speeches praising the project outside a TxDOT office in North Austin. They were heckled throughout by a group of about 20 protesters with the nonprofit Rethink35, which calls for replacing the highway with a boulevard. Demonstrators stood at the edge of TxDOT's property, chanting over the roar of I-35 traffic behind them.
"We're here to tell you the community opposes this expansion," Rethink35 co-founder Adam Greenfield said through a bullhorn to the crowd of officials and TxDOT employees gathered under a tent with coffee, cookies and breakfast tacos. "Please stop the project while a judge determines the outcome of this case."

The I-35 CapEx North project is one of three plans to enlarge I-35 through Travis County. Construction has already started on the southern section from Ben White Boulevard to State Highway 45 East. Work on the most contentious and most expensive of the three projects — I-35 from Ben White to U.S. 290 — is expected to start next year.
The decision to break up the I-35 expansion through Travis County into three parts is the subject of a federal lawsuit by Rethink35 and other advocates who allege the move was intended to skirt a more thorough federal environmental review. TxDOT has denied this in court filings.
Expanding the highway through North Austin requires TxDOT seize at least 17 acres of additional land, according to the state's environmental review. Property owners receive financial compensation and relocation help if needed. The land acquisition is displacing five businesses: GTO Auto Wheels, Pickup Heaven, A-1 Tires, Thermo King of Austin and the offices of another auto business.
The I-35 North project been criticized by the Austin City Council, most fiercely by District 4 Council Member Chito Vela, who has demanded TxDOT add more east-west crossings over I-35 for cars, bikes and pedestrians.
"You can see just huge distances [between crossings]. I think the average is well over a mile," Vela said at a council meeting last month while showing a map displaying 11 crossings over I-35 Capital Express North. "That's just too far to go."
Vela did not respond to a request for comment before this story was published.

A broader critique of the project stems from a concern that expanding highway capacity will incentivize more driving as people take advantage of faster travel times in the short-term, leading to an overall increase in traffic in the long-term.
"Adding highway lanes in the middle of Austin is pointless and a waste of money," said Jay Blazek Crossley, executive director of the nonprofit Farm&City, which advocates for safer streets.
Crossley, who lives a mile from I-35 in North Austin, calls the highway "the most dangerous thing" in the city and says it has to be fixed. He doesn't think TxDOT's plan is ideal, but says the state agency has made some moves to improve safety.
"They've already fixed the St. Johns [Avenue] crossing, and they made it a lot better. That kind of thing is what we need," Crossley said. "Fixing very broken, failed things that were designed poorly in the past."
The St. Johns Avenue Bridge was replaced last year with a new crossing that provides two lanes in each direction with a center turn lane along with U-turn bridges for both northbound and southbound traffic.
Construction on the I-35 CapEx North Project is not scheduled to be complete until late 2028, weather permitting.
Correction: This story has been corrected to indicate that CapMetro bus routes currently using this section of I-35 North cross the freeway rather than travel along the main lanes.