Ignacio Garcia, “Underground highway would have built-in safety features,” KXAN, June 26, 2013

A dramatic scene played out on Austin’s busiest roadway Monday when flames engulfed a tractor trailer on Interstate 35 near Riverside Drive. Witnesses described explosion and large flames shooting out a trailer loaded with pork bellies.

Eight hours later, the roads finally reopened.

New plans to move a section of the interstate have raised several questions, including what would happen in the event of a large fire in the tunnel?

“An accident inside a tunnel would make things a little bit more difficult, but no more difficult I would assume than what we had yesterday when we had to block off the entire southbound lanes,” said Palmer Buck with the Austin Fire Department. “We just have to work on contingency features if we did have a wreck in that facility how we’d move traffic around.”

Those are the challenges the fire department would have to consider as cut and cap supporters move towards burying a stretch of the interstate to create a tunnel that would add 30 acres of parks, stores and office space above.

“If you’re underground you have to have standard pipe systems that we can hook up to,” Buck said, “as well as some other protection systems and exits, if they are trapped in the tunnel, to exit out of.”

Safety was one of the topics in Tuesday’s open house at Akins High School as Austinites met to discuss future highway designs of the busy interstate. The idea of a “depressed” highway design is one of two being discussed.

“They could be built to have caps on top of them, not for the entire segment but for pieces of it,” said Kelli Reyna with TxDOT. “You could have caps on the depressed sections.”

(TxDOT’s) Reyna says all safety infrastructure for emergency services would be built, including built-in escape routes underground. “They are depressed main lanes, but the frontage roads would remain on the sides of the roadway,” she said. “That’s so that you can continue to have access onto and off of I-35.”

The cut and cap plan idea is still years away, but firefighters say they’ll be ready for whatever happens, whether it’s a capped tunnel or open road.