South Austin drivers who count on William Cannon Drive to hop over I‑35 are in for a couple of bumpy weekends. TxDOT will close the William Cannon bridge over I‑35 overnight for two consecutive weekends starting Friday night, May 29, with full closures from 10 p.m. Friday to 5 a.m. Monday on May 29–June 1 and again on June 5–June 8. Anyone who normally uses the crossing should bank on detours and delays during those hours.
Why crews will shut the bridge
Construction teams will be lifting large beams into place for the elevated managed lanes that are part of the I‑35 Capital Express South project. Because those beam placements require heavy equipment and precise staging over the highway, the entire bridge has to be closed so crews can work safely, according to MySA.
Detours and traffic impacts
During the closures, eastbound drivers on William Cannon Drive will be routed to the I‑35 frontage road to reach southbound I‑35, or can use the U‑turn at Slaughter Lane to loop back north. Westbound drivers will be directed to turn right onto the frontage road to get to the northbound I‑35 or use the U‑turn at Stassney Lane to head south. On top of that, drivers should expect lane reductions on the I‑35 main lanes and both frontage roads throughout the two closure weekends, according to Community Impact.
Where this fits in the project
The Capital Express South project runs from SH 71/Ben White Boulevard to SH 45 Southeast and is set to add two managed/HOV lanes in each direction, a southbound bypass lane, reconstructed ramps, and new pedestrian and bicycle paths. The multi‑phase effort, estimated at roughly $548 million, kicked off in 2022 and is expected to wrap up in late 2028, according to TxDOT.
How to plan your trip
TxDOT is urging drivers to follow posted signs, stay alert in the work zone, and build in extra travel time while the closures are in effect. The agency has also posted detour graphics and a map video on the project website, per TxDOT. Local traffic reporters note that while the shutdowns are limited to overnight weekend windows, they will almost certainly tangle late‑night and early‑morning commutes, so it is worth checking local traffic pages before heading out, as reported by MySA.
