State highways are getting sprayed with a magnesium chloride to lower the temperature at which ice can form. TxDOT has finished pre-treating major roadways and is now focusing on stretches of secondary roads where ice could form, like on bridges or overpasses.
Meanwhile, in Austin, the city has not pre-treated any roads. The main reason? Concern about runoff.
"In the City of Austin, we are really lucky to have thousands of miles of creeks," said Pirouz Moin, assistant director at Austin's Department of Public Works. "A lot of this runoff directly ends up into those creeks, into environmentally sensitive areas."
Unlike Northern U.S. cities that get pounded with snow for weeks and have streets so heavily salted that shoes and vehicles get stained white, Austin's ice tends to melt on its own within a day or two.
"If it was over a number of days, then that risk-to-benefit is completely different," Moin said. "It would make sense to have that pre-treatment application and keep those roadways open for days."
In recent months, the city has begun internal conversations with water and environment officials to determine where it could be safe to pre-treat roads. Moin wouldn't say when a decision could be made or if it could be this winter.
"We are hoping soon to have an agreement to let us start a test section," he said.
In the meantime, the city does treat roads after they get slippery.
Nine trucks are on standby and ready to spread a coarse sand made of dolomite on icy streets. Crews are checking temperatures on elevated roadways like bridges and overpasses, and examining ice accumulation.
