CHICAGO (CBS) — Authorities are warning people to stay off the roads ahead of the winter storm, scheduled to hit the area after 6:00 p.m.

The Illinois Department of Transportation says the storm has the potential to dump more than a foot of snow throughout northern Illinois.

The agency says the storm will bring limited visibility and extremely long travel times are anticipated.

““The IDOT team is fully prepared to work around the clock to keep roads as free of snow and ice as possible,” says Illinois Transportation Secretary Randy Blankenhorn.

“Before getting behind the wheel, please ask yourself if your trip is really necessary. Consider taking public transportation or postponing your trip,”says Blankenhorn.

“If you must drive, be prepared to add plenty of extra time in your schedule.”

IDOT says its crews are preparing trucks in anticipation of the storm.

According to the National Weather Service, snow is expected to fall between 6:00 and 8:00 p.m.

IDOT cautions people who are on the road not to crowd snow plows and to take it slow, especially when approaching intersections, ramps and bridges.

Motorists are also encouraged to have a full tank of gas and to have a cellphone charged.

People should have food, a warm blanket, water, a first-aid kit, washer fluid and an ice scraper in their vehicles.

For roadway assistance, people are to call #999 in the Chicago area and to always use seat belts in the front or backseat.