Travel disruptions began to spike around Maryland as a winter storm affecting millions barreled across the Midwest and the South toward the East Coast on Friday.

The storm, which could bring about a foot of snow and a layer of ice to the Baltimore area starting on Saturday evening, is expected to interrupt travel for several days, according to the National Weather Service. Airlines, Amtrak and local transit are already bracing for the storm’s impact in cities from Dallas to New York. Gov. Wes Moore urged drivers to stay off the roads in a press conference on Friday.

Over 3,500 flights nationwide were delayed or canceled by Friday evening, according to FlightAware, a flight-tracking website. Flight delays and cancellations slowly ticked up by the hour at nearby airports as well. Washington Dulles International Airport had about 74 delays and nine cancellations by Friday evening, while Ronald Reagan Washington National Airport had 114 delays and 14 cancellations.

Baltimore-Washington International Thurgood Marshall Airport was less impacted, with 36 delays and four cancellations on Friday evening. But Jonathan Dean, a spokesperson for BWI, said airlines may cancel flights through the weekend and might allow travelers to alter travel plans ahead of the storm.

About 150 airport employees will focus on removing snow from airport runways and taxiways, he added. If travelers need to park at the airport, parking garages and covered parking spaces should be available.

Ahead of the snowfall, Amtrak also canceled dozens of trips in the Northeast and the mid-Atlantic for Friday, Saturday and Sunday. The cancellations include many of the Northeast Regional and Palmetto trains, which make stops at BWI and Baltimore’s Penn Station.

Amtrak is offering rebooking options and refunds without penalties to customers who have their trips canceled due to the weather, according to a Friday announcement.

The Maryland Transit Administration warned commuters that public buses and trains could be detoured or modified depending on weather conditions. MTA announced that the Charm City Circulator will end its service at 10 p.m. on Saturday and will resume at noon on Sunday. Commuter bus route 201 will stop running at 5 p.m. on Saturday and remain out of service through Sunday.

The MTA will keep customers updated on changes to local transit routes on its website. The site also features a list of bus routes that would be affected first by a snow emergency.

On Thursday, the Baltimore City Department of Transportation began pretreating certain roads, including on- and off-ramps for Interstate 83 and Maryland 295, according to the mayor’s office.

Storm crews with the Maryland Transportation Authority are also preparing ahead of the snowstorm, but the agency has cautioned that drivers should consider changing travel plans this weekend. After a dump of snow that’s expected to start on Saturday evening, weather conditions could turn icy on Sunday, according to the National Weather Service.

MDTA will temporarily close Interstate 95 express toll lanes in Baltimore at 2 p.m. on Saturday for its crews to prepare for snow removal operations. Drivers will be detoured to the adjacent mainline traffic lanes. The express toll lanes will reopen “when conditions permit,” MDTA said, adding that updates on major incidents will be provided on X.

State officials warned drivers to keep an emergency supply kit in their car if they must travel, including first-aid items, flashlights, batteries, snacks, water, warm clothing and blankets.

This story has been updated.