Construction on the $107 million project started in August 2021 and is anticipated to be completed in April. The goal of the project was to widen the I-35 bridge over SH 123, requiring several lane closures and detours throughout the nearly four years of construction.
Data shows that road safety decreased while the project was taking place. In 2020, there were 55 accidents on SH 123, and accidents rose to 80 in 2024, an increase of about 45%.
The big picture
Since 2022, traffic accidents in San Marcos have increased by nearly 13%, according to data from TxDOT. In that same period, San Marcos’ population has also grown significantly, increasing by nearly 30% since 2020, adding to congestion concerns.
In response, San Marcos and TxDOT officials have initiated various projects to improve roadway conditions and traffic flow, including the following:
- I-35 alternate route FM 110 North, completed January 2024
- Hopkins Street and Guadalupe Street intersection improvements, completed June 2024
- Hopkins Street improvements, estimated completion by November 2029
Current situation
San Marcos is expected to grow at an annual rate of 4.56%, putting the estimated total population at 142,145 by 2035, according to the city.
In 2024, there were a total of 1,503 traffic accidents, with at least 580 accidents on I-35, according to TxDOT. Nearly 34% of all 2024 accidents took place at an intersection.
Excluding I-35, the major roadways in San Marcos that saw the highest number of accidents in 2024 were Loop 82 and SH 123.
Other minor roadways also saw elevated traffic accidents, including Clarewood Drive with 15 accidents and Sessom Drive with 17 accidents, according to TxDOT data.
FM 110, which opened in 2024, saw fewer accidents in 2024 than all major and smaller roadways in San Marcos.
Stan Standridge, San Marcos Police Department chief, said in a statement that in 2022, there were 16 fatalities in San Marcos, with most occurring on I-35 and SH 123.
How we got here
A 2024 Consumer Affairs study ranked San Marcos drivers the second worst in Texas among cities with populations over 50,000. The city had the second-highest rate of driving fatalities in 2022 and ranked fourth in Texas for deaths involving a positive blood alcohol content per 100,000 people.
“Approximately 75% of these crashes involved alcohol or drug use, and many were due to speeding,” Standridge said in the statement. “In 2023, the number increased to 19 fatalities, with SH 123 surpassing I-35 as the top fatality roadway, largely due to speed and substance use.”
TxDOT Southwest Communications Director Brad Wheelis said that TxDOT relies on drivers to act responsibly.
“Even one traffic death is one too many,” Wheelis said in the statement. “Over the past five years in San Marcos, the top contributing factors in crashes on TxDOT roadways were speed, driver inattention and alcohol.”
What residents are saying
Local resident Danielle Johnson said that since moving to San Marcos nearly four years ago, she has been in two car accidents.
“I’m terrified of getting into another accident, especially because none of the accidents that we’ve been in have been our fault,” Johnson said. “Sometimes I avoid driving on certain roads or the highway because I don’t want to deal with being involved in another accident.”
Local resident Kelly Keefer said after she and her 10-year-old son were T-boned in July at Posey Road, she and her family will be moving to Iowa to get away from the growing traffic in San Marcos.
“We’re tired of living our lives stuck in traffic, and so we kind of want to get away from it all ...” Keefer said. “I have major anxiety about [driving] now. Even my son ...when he rides in the car with me, he’s always just like on edge. I just try to avoid [driving] as much as possible.”
What’s being done
As of April 11, there have been 399 accidents in 2025, a 2.31% increase from the same period in 2024. Of the 399 accidents, 115 were on I-35, 48 on Loop 82 and 15 on SH 123, per TxDOT data.
Standridge said the city and SMPD are working to reduce traffic accidents through a dedicated traffic unit targeting high-collision areas.
In 2022, Capital Area Metropolitan Planning Organization, or CAMPO, partnered with San Marcos to study SH 123, SH 80 and I-35, aiming to improve the corridors to support the city’s rapid growth, according to Community Outreach Manager Doise Miers.
“It can definitely be frustrating for those that want to see improvements ... but it’s a process, and it’s a process for a reason,” Miers said.
Previous projects, like the Loop 82 reconstruction at I-35 and Aquarena Springs, and FM 110 opening in 2024, aimed to improve road conditions, reduce accidents and encourage drivers to use alternate routes to ease I-35 congestion.