Weather permitting, Webber LLC expects to deliver the Texas Department of Transportation's (TxDOT) $107 million Interstate 35 at State Highway 123 project in San Marcos by the end of the year. Work began in August 2021.
Five benchmarks are completed: the construction of a southbound I-35 frontage road north of SH 123, including the San Marcos Bridge; the reconstruction of the northbound I-35 frontage road south of SH 123; the reconstruction of northbound I-35 main lanes; the reconstruction of southbound I-35 main lanes; and the reconstruction of the SH 123/I-35 intersection and C.M. Allen Parkway exit (#204B).
The remaining work on the TxDOT priority project focuses on final paving and striping.
Photo courtesy of Texas Department of Transportation
"I-35 through the heart of Central Texas is an important artery connecting South Texas to the DFW area and beyond," said Antonio Luján, a TxDOT public information officer. "Improvements to this area are needed to address congestion that occurs on the main lanes, frontage roads and cross-street intersections. The project aims to improve mobility and safety at the I-35 and SH 123/Guadalupe Street intersection and the ramps between SH 80 to RM 12."
This project includes reconstructing and improving the SH 123 intersection and the I-35 main lanes and bridge over SH 123/Guadalupe Street; reconfiguring ramps along the north and southbound frontage roads between SH 80 and RM 12; reconstructing portions of the north and southbound frontage roads, including the bridges over Willow Springs Creek and the San Marcos River; and improving bicycle and pedestrian accommodations. It also includes improvements to the northbound and southbound I-35 frontage roads and bridges at the San Marcos River.
The project is financed by the Capital Area Metropolitan Planning Organization (CAMPO) and TxDOT.
An environmental study was completed in August 2017, and the schematic/design development process was completed in mid-2021. The project was designed by Volkert Engineering.
The work is part of the Mobility35 program to improve a 79-mi. stretch of I-35 in Hays, Williamson and Travis counties.
The I-35 San Antonio/Austin stretch of I-35 connects a booming region with a combined population of about 5 million people covering 100 mi. from South San Antonio to Georgetown. Traffic counts through the 100-mi. corridor exceed 100,000 vehicles daily per day — Austin to San Antonio.
The project has proven complicated, but TxDOT said Webber is prepared.
"Webber is proactive at working to complete projects ahead of schedule," the TxDOT team said. "This project is progressing, and we are ahead of the engineers' original estimated schedule and days bid."
Utilities are always a challenge, and some phasing changes were needed to work around utilities that weren't relocated within the original timeframe.
"Construction occurs during the day and at night when needed," TxDOT added. "Our crews try to plan traffic shifts and necessary lane closures during the least impactful times of the day. The positive partnership with Webber opens the door to a successful outcome. We work as a team to find solutions as the project moves forward."
Meantime, road surfaces vary.
"Both asphalt and concrete roads were used in this project — hot mix and continuously reinforced concrete on the main lanes and hot mix on all frontage roads," TxDOT said, noting that the project should last for decades, "A general expectation for a bridge structure lifespan is approximately 75 years. TxDOT has a robust inspection program that will monitor these structures through their lifespan."
The reconstruction and improvements of the SH 123 intersection and the I-35 main lanes and bridge over SH 123/Guadalupe Street are on schedule.
"Lanes weren't added, but the width was increased for possible future lanes," TxDOT said. "In partnership with the city of San Marcos, TxDOT upgraded the sewage and water lines where the existing lines would have conflicted with the new construction. Additionally, all the existing drainage was upgraded to new standards."
Photo courtesy of Texas Department of Transportation
The reconfiguration of the ramps along the north and southbound frontage roads between SH 80 and RM 12 is done.
The reconstruction of portions of the north and southbound frontage roads, including the bridges over Willow Springs Creek and the San Marcos River, has progressed smoothly.
The northbound and southbound I-35 frontage roads and bridges at the San Marcos River are complete, too.
"The northbound frontage bridges at Willow Springs Creek and San Marcos River were the first milestone in the project," TxDOT said. "We had to completely close the northbound frontage road to simultaneously reconstruct both bridges.
"Webber had 86 days to complete this from the time traffic was detoured from the frontage road. Webber exceeded this expectation and opened the frontage road in 67 days. Along those same lines, the southbound frontage road at Willow Springs was completed in 56 days rather than the anticipated 76 days."
Four northbound and the southbound frontage bridges were demolished as well.
As usual with extensive projects, excavators, dozers, rollers, compaction equipment, asphalt-paving machines, smaller excavators, skid loaders, concrete trucks and boring machines for utilities were all used, although Webber did not set up any concrete and asphalt batch plants for the project.
Webber uses a combination of on-site mechanics and additional maintenance people sent in as needed on the project. The company buys and rents equipment from regional and local equipment dealerships. CEG
