The dense fog that has hampered holiday travel this week should ease today as more than 525,000 cars hit Maryland highways on the year's busiest travel day.
For two consecutive mornings, motorists and commuters battled thick fog, and visibility was less than a mile for most of yesterday, tying up area roads.
"People are moving really slowly," Valerie Burnette Edgar, spokeswoman for the Maryland State Highway Administration, said yesterday. "You can barely see on some roads."
The State Highway Administration has 85 cameras monitoring traffic flow and accidents. Officials said yesterday that Interstates 95 and 395 in Baltimore County had the state's foggiest conditions and worst traffic tie-ups.
"We are looking at the Interstate 95 interchange with Interstate 395 right now and you cannot see out of the camera" because of fog, Burnette-Edgar said at 5 p.m. "But there have not been as many accidents as you would think. It's more just fender-benders."
Despite the fog, Baltimore-Washington International Airport had only slight departure and arrival delays yesterday, said Marilyn Corbett, an airport spokeswoman.
BWI expects 58,000 people -- 17,000 more than normal -- to pass through its terminals today, airport officials said yesterday. With Maryland's road volume, AAA expects more than 6 million people nationwide to travel by air, rail or ship by midnight tonight.
John M. Margraf, a meteorologist at the National Weather Service in Sterling, Va., said foggy conditions this week were caused by cool, moist air from the Atlantic Ocean.
The fog settled because of light winds along the East Coast from New York to North Carolina, Margraf said.
Foggy conditions should persist until noon today, when a southwest wind will churn up stagnant air, causing the fog to dissipate, Margraf said.