The project aims to improve congestion and safety in the rapidly growing San Marcos area. It includes intersection improvements at I-35 and Hwy. 123 as well as ramp reversals along I-35 between Hwy. 80 and RM 12.
“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, and this project will satisfy those increased demands and meet the needs of our growing city,” San Marcos Mayor Jane Hughson said.
According to the TxDOT website, the transportation agency will also reverse two ramps along the northbound frontage road between Hwy. 80 and Hwy. 123 and reverse one on the southbound frontage road of the same stretch. It will also realign the southbound exit ramp to Hwy. 123.
TxDOT Austin District Engineer Tucker Ferguson said the ramp reversals will enhance safety in the increasingly congested region.
“If you have the traditional diamond intersections, a lot of traffic getting off it could potentially back up onto the main lanes, so really it's a safety issue when you have high volumes of traffic,” he said. “It gives us more capacity to store people coming off on the frontage road.”
In addition to ramp and intersection construction, the project intends to make improvements to bicycle and pedestrian accommodations along the frontage roads and reconstruct the frontage road bridges over Willow Springs Creek.
The project is a part of the Mobility 35 program, which aims to improve I-35 along a 79-mile stretch that goes through Hays, Williamson and Travis counties.
“This is the 20th project we've broken ground on in the last 10 years of developing the Mobility 35 program,” Ferguson said.
The groundbreaking comes amid a flurry of I-35 projects, as TxDOT is currently evaluating a major overhaul of the stretch from SH 45 N to SH 45 SE in Austin as well as major projects in the New Braunfels area.
According to the TxDOT website, construction for the project at Hwy. 123 is estimated to cost $107 million, with funding coming from TxDOT and the Capital Area Metropolitan Planning Organization. More intensive construction is scheduled to start in late 2021, and construction is anticipated to be complete in early 2025.
Editor's note: This story was updated to correct Tucker Ferguson's title.