Austin, September 28, 2025
News Summary
A section of I-35 in South Austin will be closed overnight due to construction for the I-35 Capital Express South project. All southbound lanes will be shut from 9 p.m. Saturday to 10 a.m. Sunday, requiring drivers to take detours. The multi-million dollar project aims to improve traffic flow by adding high-occupancy vehicle lanes. Additional closures for the Stassney Lane bridge are also planned over the upcoming weekends.
Austin
A stretch of I-35 in South Austin will be closed from 9 p.m. Saturday to 10 a.m. Sunday due to construction activities associated with the I-35 Capital Express South project. All southbound lanes of I-35 between State Highway 71/Ben White Boulevard and Stassney Lane will be shut down during this period.
The construction involves placing steel beams as part of a multi-million dollar initiative aimed at improving traffic flow in South Austin. The I-35 Capital Express South project is designed to add two high-occupancy vehicle (HOV) lanes in each direction along this busy corridor.
Drivers should expect several detours during the closure. Westbound drivers on SH 71 are advised to take the northbound exit to I-35, exit at Oltorf Street, and then utilize the U-turn to re-access I-35 southbound. Eastbound drivers on SH 71 should take the Congress Avenue exit and use the I-35 frontage road for detours.
Project Overview
The I-35 Capital Expressway South Project has an estimated budget of $548 million and will be completed in four phases. It includes significant infrastructure changes such as a long elevated section of roadway, aimed at alleviating congestion in the area.
Key features of the construction include the development of massive concrete pillars and caps that will support the elevated roadway. Around 95 to 100 pillars are planned, with caps approximately 100 feet wide, significantly larger than standard construction materials.
A substantial amount of materials is required for the construction, including 79 tons of prestressed girders, an equivalent weight to that of eight Eiffel Towers and 700 fully-loaded railroad cars. Advanced planning has been conducted to mitigate supply chain issues for the necessary materials.
To further streamline the construction, a concrete plant will be built by the main contractor, Flour Corporation, to avoid straining local resources. Part of the improvements will include flattening a steep slope around Onion Creek to assist truck movement.
Additional Road Closures
Alongside the weekend closure on I-35, the Stassney Lane bridge over I-35 will also close for the next two weekends, starting at 9 p.m. Friday and reopening at 6 a.m. Monday. This is part of the larger infrastructure improvement associated with the I-35 Capital Express project.
Project Timeline
The entire I-35 Capital Express project is anticipated to be completed by late 2028 or early 2029. The efforts are directed at long-term enhancements to the traffic flow and overall road safety within South Austin.
Conclusion
As roadwork proceeds, officials encourage drivers to plan ahead and remain aware of the ongoing changes to traffic patterns in the area.
FAQs
What are the closure times for I-35 in South Austin?
A stretch of I-35 in South Austin will be closed from 9 p.m. Saturday to 10 a.m. Sunday.
Which lanes will be closed during the construction?
All southbound lanes of I-35 between State Highway 71/Ben White Boulevard and Stassney Lane will be shut down.
What is the purpose of the I-35 Capital Express South project?
The project aims to add two high-occupancy vehicle (HOV) lanes in each direction along a busy corridor.
How much is the estimated cost of the I-35 Capital Express South project?
The project is estimated to cost $548 million and will be completed in four phases.
What should drivers expect during the closure?
Drivers are advised to expect several detours during this closure.
When will the Stassney Lane bridge over I-35 be closed?
The Stassney Lane bridge over I-35 will also be closed for the next two weekends, starting at 9 p.m. Friday and reopening at 6 a.m. Monday.
Key Features of the I-35 Capital Express South Project
| Feature | Details |
|---|---|
| Closure Times | 9 p.m. Saturday to 10 a.m. Sunday |
| Construction Area | Southbound I-35 between State Highway 71/Ben White Boulevard and Stassney Lane |
| Project Cost | $548 million |
| Completion Timeline | Late 2028 or early 2029 |
| Pillars Planned | 95 to 100 |
| Weight of Materials | 79 tons of prestressed girders |
| Additional Structure | Elevated roadway |
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Additional Resources
- KVUE News: I-35 Closure
- Wikipedia: Interstate 35
- FOX 7 Austin: I-35 Expansion
- Google Search: I-35 Capital Express South project
- Community Impact: I-35 Updates
- Google Scholar: I-35 Capital Express South project
- Austin CultureMap: I-35 Construction
- Encyclopedia Britannica: Lady Bird Lake
- KXAN News: I-35 Construction Near Lady Bird Lake
- Google News: I-35 Capital Express South project
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