David Spear estimated the state has spent close to $5 million since Sunday to clean up the storm that has left the Atlanta area crippled for three days. He said the department aims to have all roads under state control cleared by Friday.
"We are making progress, but it's slow and arduous," Spear said. "It'll get better every day."
The state is trucking in thousands of tons of salt and gravel to help clear treacherous interstates and roads. So far, DOT has used at least 10,000 tons of the deicing mixture on roads.
Spear said crews had about 99 percent of state roads passable by Wednesday night.
Forecasters say thawing will be slow as temperatures will remain in the teens at night and likely won't warm into the 40s until Friday.
"While road conditions are improving and have improved on the southern end, the amount of snow farther north that was water or slushy, that's going to refreeze," said Brian Lynn with the National Weather Service in Peachtree City.
UPS deliveries were getting back to normal on Wednesday after two days of delays from ice-coated roads across the Southeast. However, just as the Atlanta-based firm was getting caught up in the Southeast, drivers were dealing with winter weather in the Northeast.
Though UPS was back up and running Wednesday, its trucks were not always able to deliver items in the Atlanta area because many businesses remained closed due to the storm, UPS spokeswoman Susan Rosenberg said.