CONSTRUCTION COMING: TxDOT breaks ground on Interstate 35 at SH 123 project

With cars whizzing by on Interstate 35, the Texas Department of Transportation broke ground on its upcoming I-35 at State Highway 123 project in San Marcos. 

TxDOT officials were joined Wednesday by Hays County Commissioner Pct. 2 Mark Jones and San Marcos Mayor Jane Hughson at a ceremony marking the project's beginning. 

“In fact this is the 20th project that we’ve broken ground on in the last 10 years of developing the Mobility35 program,” TxDOT Austin District Engineer Tucker Ferguson said. “This section of I-35 carries a little over 150,000 vehicles a day. So, it’s very important that we improve safety, address congestion, address mobility and continue with the growth that we’ve seen in San Marcos and Hays County.” 

The I-35 at SH 123 project aims to improve the intersection between the two highways. It will include the reconstruction of the intersection and will also reverse entrance and exit ramps between State Highway 80 and RM 12. The project will include the reconstruction of the northbound and southbound I-35 frontage roads, including the northbound bridges over Willow Springs and the San Marcos River. 

“We will extend the exit and entrance ramps to make them more efficient and safer, and enhance bicycle and pedestrian accommodations throughout the corridor, which is becoming a more common thing on all of our projects as we look at different modes throughout our corridor,” Ferguson said. “So, we’re excited to start this key mobility project, which will improve the quality of life for those in Hays County living in San Marcos.” 

According to TxDOT, The project is expected to occur in phases until completed in early 2025, weather permitting. 

The first phase will begin with the reconstruction of the northbound I-35 frontage road north of SH 123 and the bridges over the San Marcos River and Willow Springs.

The second and third phases will involve the reconstruction of the southbound I-35 frontage road that is north of SH 123 and the northbound I-35 frontage road that is south of SH 123. This will include the San Marcos River bridge.

Phases four and five will consist of the reconstruction of the northbound and southbound I-35 mainlanes.

The sixth phase will see the reconstruction of the SH 123 and I-35 intersection and the C.M. Allen Parkway exit. Phase seven will be the final paving and striping to finish off the project.

“I want to thank TxDOT and our continued partnership to ensure we are moving forward the many needed projects to provide the best possible solutions to address safety, mobility and connectivity in Hays County and our region,” Hays County Commissioner Pct. 1 Debbie Gonzales Ingalsbe said in a statement.

The project is expected to cost $107 million. Hughson said the I-35 at SH 123 project will “greatly benefit San Marcos — its residents and visitors as we travel through this area.” 

She added that the project will address flooding issues at Sunset Acres and will help San Marcos during flash flood events by raising part of the frontage road. 

“Our population is growing and there are more visitors coming to our city so it’s vital that we meet the needs of this ever increasing volume of traffic safety,” Hughson said. “This project will satisfy those increased demands and meet the needs of our growing city. We know that to make an omelet you’ve got to break some eggs. We will try to be patient and keep focused on the mobility and safety improvements this will bring to our community and we look forward to its completion in 2025.”

Additional reporting by Alyssa Gonzales