Get There

For those of you working or needing to get around in Maryland today: The Maryland Transit Administration will have regular service on local buses, the Metro and the light rail today. There's also no MARC and no commuter buses today. For more information, visit the MTA website.

Updated 10:36 a.m.
Arriving flights are no longer being delayed by foggy conditions in the Washington area, the Federal Aviation Administration reported.

Dense fog in the Washington area had prompted a ground stop for flights arriving at all three Washington-area airports Thanksgiving morning. But by 10:30 a.m., the problem appeared to be over, according to an FAA Web site that tracks flight times.

Early morning delays were reported for arriving flights at Washington Dulles International Airport, Ronald Reagan Washington National Airport and Baltimore-Washington International Airport. Departing flights were apparently not affected.

A fog advisory was in effect for the Washington region inthe early morning, with visibility near zero in some places. Area roadways were reportedly clear, however, with traffic light. Meteorologists said the fog should lift later in the morning, giving way to clear skies and temperatures near 60 degrees.

Thanksgiving Day traffic: Many people will be making trips of two to four hours for holiday visits, but overall, traffic will be light in most areas. Watch out for I-95 traffic north of Baltimore and southbound approaching the Wilson Bridge on Thursday.

The holiday rules regarding lane restrictions and parking apply on Thursday. You won't encounter road construction in the Washington region tonight or through the weekend. The Virginia Department of Transportation will switch the timing on signal lights around 14 big shopping areas in Northern Virginia for the holiday season, starting on Thanksgiving Day. The intention is to limit congestion and maximize traffic flow on the main roads.

Here's a rundown of the local train and bus schedules for Thursday, as assembled -- very helpfully -- by Metro.

Metrorail: Sunday schedule; opens at 7 a.m., closes at midnight.
Metrobus: Sunday schedule
MetroAccess: Sunday schedule; operates from 7 a.m. to midnight.

Ride On: Sunday schedule
DASH: No Service
CUE: No Service
Fairfax Connector: Sunday schedule on Routes 101, 151, 152, 161, 162, 171, 310, 321, 322, 401, 425, 505, 574, 605, 950, and RIBS 1, 2, 3, 4
ART: Sunday schedule on Routes 41 & 51 only
THE BUS: No Service
PRTC OMNIRIDE: No Service
LOUDOUN BUS: No Service
MARC: No Service
VRE: No Service
MTA Commuter Bus: No Service

As with VRE, Maryland's afternoon train service could be affected by the CSX freight train derailment south of Washington on Tuesday.

The Maryland Transit Administration says trains are starting to get through the CSX derailment. As a result, there may be some delay to MARC trains on the Camden and Brunswick lines this afternoon as the freight congestion clears.

Here's a link to the MARC Tracker, which shows the location of commuter trains.

Update (3:55 p.m.): According to the Federal Aviation Administration, delays in Boston were averaging 48 minutes; at Newark 1 hour and 6 minutes; at Philadelphia 2 hours and 21 minutes.

Spreading weather-related delays in the Northeast are slowing air travel, potentially upending what had been a smooth but busy air travel day.

Some departing flights from Dulles and Reagan-National airports are being delayed because of slowdowns in Boston, Newark, New York and Philadelphia caused by excessive low-level cloud cover. Dulles and Reagan-National are experiencing similar weather conditions, according to the FAA.Travelers should check with their carriers for the latest information about flight delays, which is changing frequently.

Excessive low-lying cloud cover makes it more difficult for pilots to take off and land. As a precaution, controllers generally space out airplane landing intervals. Mike Pigott, a meteorologist at Accuweather.com, said the weather conditions are expected to remain throughout the day.

-- Sholnn Freeman

If your big holiday trip amounts to no more than a short visit with nearby relatives, followed by a Friday commute or shopping excursion, there still are plenty of reasons to be prepared and alert.

Traffic
Friday is not a holiday. The regular weekday rules are back in effect. Watch the reversible lane indicators and pay those parking meters. However, you will not encounter any local road construction on Friday or through the weekend.

Metrorail
The trains will run on a regular weekday schedule from 5 a.m. Friday to 3 a.m. Saturday. Trains on all lines will operate with six cars. Typically, Metrorail ridership the day after Thanksgiving is relatively light. Last year, Metrorail recorded 393,775 passenger trips, which is closer to ridership for a typical Saturday.

Shopping traffic
It's not the busiest shopping day of the season, but the traffic around the malls and the crowding in the parking areas does come as quite a shock for many on Black Friday.

Virginia traffic signals: The Virginia Department of Transportation will change the timing on traffic signals around 14 big shopping centers in Northern Virginia to cut down on delays and maximize traffic flow on the main roads. (Maryland uses a different signal system.)

This year, the signal switch will start on Thanksgiving Day, rather than on Friday. Traffic planners noted last year that volume started to build up a bit on Thanksgiving Day itself. The signals will remain on this seasonal timing through New Year's Day.

Some people get kind of anxious about the shopping thing. Tysons Corner Center, for example, plans to open at the stroke of midnight on Thanksgiving night. (That's 12 a.m. Friday.) But shoppers should check here to see when their store will be open.

VDOT has been retiming the signals based on holiday traffic patterns for more than a decade. This year, it developed new signal-timing plans for two more shopping centers, the Leesburg Corner Premium Outlets and the Dulles 28 Centre in Loudoun County.

This re-timing affects how drivers get through 188 intersections across Northern Virginia. Here's the full list of shopping areas where the signals are being adjusted:
Tysons and Galleria Shopping Centers, Reston Town Center, Fair Lakes Shopping Center, Fair Oaks Mall, Potomac Mills Mall, Manassas Mall, Route 234 shopping centers, Springfield Mall, Cascades Town Center, Potomac Run Center, Dulles Town Center

In parking areas
Pushing so many people together in parking areas raises security and safety concerns. Here's some advice from police and traffic experts.

Security: Park in a well-lighted space. Lock the car, close the windows and put the shopping bags and gifts in the trunk. Don't leave a GPS unit in plain sight. Even the telltale ring of the GPS suction cup on the windshield is an invitation to thieves.

Safety: Montgomery County recently discovered that a fifth of its pedestrian accidents happen in parking areas. Similarly, the Insurance Institute for Highway Safety says that a fifth of all vehicle collisions that result in damage claims occur in parking lots. Drivers and walkers need to pay attention to each other, proceed slowly and turn their heads to look for trouble.

AAA Mid-Atlantic and other safety advocates offer these tips for staying sane and safe during holiday shopping:

-- Avoid petty confrontations over parking spaces. "Tempers can run high and patience short as drivers circle the parking lot in search of an empty parking space," says John B. Townsend II of AAA Mid-Atlantic.
-- Most malls have secondary entrances with less of a concentration of parkers around them.
-- Outlying areas in parking lots normally have more open spaces, lighter traffic and a lower risk of collision. And it doesn't hurt to walk off the holiday calories. But be conscious of the security issues mentioned above.
-- Use your headlights in parking areas. Help other drivers and pedestrians to see you coming.
-- Avoid parking between tall SUVs or minivans. It might be hard to see oncoming people and cars when you back out later. (I know: You control where you park, but not who will park around you while you're shopping.)
-- If you won't impede traffic flow, back into a space or pull through two spaces to park, so you won't have to reverse when you leave.
-- Children may be below your usual line of vision, and can make quick movements.
-- Practice defensive walking. Anticipate vehicle movements by looking for car exhaust or reverse lights.
-- Make eye contact. If you're not sure what the other person is going to do, stop.

1:30 p.m.: Because of the rain and mist, the two-way traffic operation that normally relieves some peak-period traffic congestion on the Chesapeake Bay Bridge is not in effect this afternoon.

The absence of the two-way traffic pattern on one of the two bridge spans and the presence of heavy eastbound traffic because of the Thanksgiving getaway means drivers should watch for crowding at the bay crossing. Some drivers will be using this route not only to reach the Eastern Shore but also to head north and hook up with I-95 in Delaware.

The Maryland Transportation Authority says it will monitor the weather conditions and could implement two-way traffic operations if and when conditions improve. Updates are available by calling 877-BAYSPAN or clicking on this link.

Also of note: The Route 90 (Ocean City Expressway) bridge is open again, well ahead of schedule. Drivers who for the past two months have used the Route 50 bridge to Ocean City and shore points north can now return to Route 90.

11:40 a.m.: According to FAA flight data, New York's major hub airports LaGuardia and Newark-Liberty International are currently experiencing weather-related delays of about 30 minutes for arriving planes. The problem is low cloud cover, which reduces visibility for landings.

Cloudy weather is holding up arriving planes at Philadelphia International Airport by 47 minutes, according to the FAA. Elsewhere, Miami International Airport has 15-minute departure delays because of thunderstorms.

However, the weather effect appears to be minimal on a nationwide basis. Flight schedules are not as heavy in the mid-afternoon period. But delays could grow worse if weather deteriorates as airline traffic picks up in the late afternoon hours.

--Sholnn Freeman

There is still track congestion from Crystal City to Alexandria following Tuesday's derailment of a freight train. So VRE says it is canceling these trains:

-- Fredericksburg Train 311, which was scheduled to leave Union Station at 6 p.m.
-- Manassas Train 335, which was scheduled to leave Union Station at 6:10 p.m.
-- The reverse flow Manassas Train 336, which was scheduled to leave Broad Run at 2:45 p.m.

Washington airports are gearing up for the late afternoon rush, just hours after successfully making it through the heavily trafficked morning departure period.

So far, Reagan National, Dulles and BWI say they haven't been hit by widespread delays related to weather, slow security screening or other hang-ups. BWI, which is expecting a big surge in travel today, said TSA agents opened checkpoints at 3:30 a.m., a half-hour earlier than usual. Many airlines at BWI also opened ticket counters earlier than normal. Now the airport is about to swing into the afternoon rush.

"It's all hands on deck," said Jonathan Dean, a BWI spokesman.

He said BWI continues to recommend that travelers arrive 90 minutes before domestic flights and two hours before international flights.

Officials at National and Dulles are urging passengers to show up two hours prior to domestic flights and three hours for international flights.

The airports also urge travelers to print boarding passes at home to speed up the check-in process.

-- Sholnn Freeman