Major state highway bridges have been pretreated with salt water to speed cleanup of the 8 to 12 inches expected to fall this afternoon into tomorrow, and all 632 state Department of Transportation plowing trucks and 200 contractor plows will be working through the night.

But with heavy snowfall expected during rush hour, drivers are urged to be especially cautious as they drive home, DOT spokesman Kevin Nursick said today.

"An afternoon commute snowfall is a worst-case scenario," he said.

Gov. Dannel P. Malloy is also urging residents to use extreme caution during the afternoon drive home and has directed non-essential state workers to leave early. Various state agencies are on staggered release times at 3, 3:15 and 3:30 p.m. He urged private employers to also dismiss workers early if possible, and directed activation of the Emergency Operations Center at 3 today to monitor conditions across the state and coordinate any assistance that may be needed.

"If you do not need to be on the road tonight, please stay home as road conditions and visibility will be deteriorating rapidly," Malloy said.

Anyone in need of shelter is urged to call 2-1-1. Malloy has asked local communities to open warming centers.

The pre-treatment applied to bridges "creates a barrier" between the snow and the asphalt, keeping the snow from packing onto the bridge deck and making it easier to clear away, Nursick said. Road conditions are expected to be particularly hazardous tonight, when high winds cause snow to drift and blow and visibility will be poor. In addition to the 25 percent salt pretreatment solution, road crews will be using a mixture of rock salt and liquid magnesium chloride during the storm to help melt the snow.

The National Weather Service has issued a winter storm warning for the entire state, and a wind chill advisory for Tolland, Windham and Litchfield counties until noon Wednesday. Wind chills of 5 below zero are predicted for tonight, with winds of 20 to 30 miles per hour and gusts up to 40 miles per hour.