AUSTIN, Texas — Texans are no stranger to the state’s roadways and the construction and traffic headaches that come with them. As the number of people on the roads increases, so does the need for more capacity.
What You Need To Know
The Interstate 35 redesign is the first major upgrade since 1974
Plans include lowering main lanes and building new drainage tunnels
The project is set to start in 2026 and complete by 2033
The Texas Department of Transportation (TxDOT) project tracker shows over 8,000 active construction projects underway or starting soon. That includes a portion of Interstate 35 in the capital city.
The work will be the first major redesign of the segment since 1974. The project is part of the I-35 Capital Express Central Project, where the main lanes will be lowered from Holly Street to Airport Boulevard.
Before that work begins, TxDOT’s Jeff Bareker explained, “That design requires proper drainage infrastructure to be in place before excavation can actually begin on lowering those main lanes.”
The project will build 6.5 miles of 22-foot diameter drainage tunnels between Airport Boulevard and Holly Street and along Cesar Chavez Street, from I-35 to U.S. 183. TxDOT is adding access shafts along I-35 for crews to access the infrastructure.
The project will also create a pump station to improve stormwater management along the corridor. To make the tunnels, two tunnel boring machines will arrive in 2026 from Herrenknecht.
TxDOT says the project is similar to others in the state, like in the ‘90s when they rebuilt U.S. 75 around Dallas, where an underground tunnel was made for drainage needs. Another example is the North Houston Highway Improvement project, which also uses a tunnel drainage system.
The whole Central Texas project is set to finish in 2033.