Traffic flows over the American Legion Bridge along I-495, the Capitol Beltway, on the day before the Thanksgiving holiday November 22, 2006 between Virginia and Maryland. (Chip Somodevilla/Getty Images)

The D.C. region’s traffic patterns are about to change in some complex ways. While it happens every year at the same time and in pretty much the same way, it can be as disconcerting to local travelers as the first couple of weeks after summer vacation or the first commute after the clocks change.

Here are some suggestions I’ve collected from veteran travelers and from experts on holiday traffic survival:

Hours and trips

Plan a shopping expedition as you would a long holiday getaway drive. Analyze your gift lists, and divide them into target zones to limit the number of trips you must make through heavy traffic. If your work hours are flexible, aim to go to stores that open early and begin your shopping expedition in the morning, when the stores and parking areas are less crowded.

Parking-area safety

The most challenging location for drivers and pedestrians is the spot they all meet: the parking lot. Seems like everybody follows his or her own set of rules. Drivers get into a big debate about whether it’s best to pull straight in or turn around to face out of the parking space . They have very strong opinions and very short fuses.

When in doubt about someone else’s intentions, resort to courtesy. Be especially alert for pedestrians. Stay in the lanes, rather than cutting across parking spaces.

And pedestrians: Don’t get so wrapped up in figuring out where you parked or worrying about whether you can juggle all those packages that you forget to keep a constant lookout for cars.

Tysons Corner

I want to pay special attention to Tysons not only because it’s a huge shopping destination, but also because there are changes in the road pattern that could help or hurt shoppers.

The Capital Beltway’s 495 Express Lanes, one of the two big construction projects that tore up the place over the past few years, are done. Drivers won’t have to navigate around orange barrels or deal with closed-off turn lanes.

But the real benefit, at least potentially, is that the project created two new ways to get in and out of Tysons. There’s one on the north side of Tysons at Jones Branch Drive and another more centrally located that connects with the Westpark Drive bridge. That’s the bridge over Route 123.

Turn left at the new traffic signal on the bridge and you’re looking at Tysons Corner Center. Turn right and you’re heading toward Tysons Galleria.

Two things I can’t tell you right now: how popular the new access points will be and how much of a toll you will have to pay to use them. The more traffic in the express lanes, the higher the toll. But before entering the lanes, you will see signs that tell you what the toll is, and you will need an E-ZPass transponder to pay them.

Traffic elsewhere

Each holiday season, the Virginia Department of Transportation customizes the signal timing at several hundred intersections to better balance the commuter traffic and the surging number of shoppers.

The signal timings are affected around these shopping areas: the Tysons malls, Reston Town Center, Fair Lakes Shopping Center, Fair Oaks Mall, Potomac Mills mall, Manassas Mall, the Route 234 shopping centers, Springfield Mall, Cascades Town Center, Potomac Run Center, Dulles Town Center, the Leesburg outlets, Dulles 28 Centre, Central Park shopping center and Spotsylvania Towne Centre.

Maryland uses a different system, with signals responding to current demand throughout the year. No matter how the signals operate, they have to be red sometime, and they can be overwhelmed by holiday traffic.

Besides those Virginia shopping areas, other hot spots include Rockville Pike, Baltimore-Washington Parkway and Route 100 near Arundel Mills, and I-295 and I-95 near National Harbor.

Dr. Gridlock also appears Thursday in Local Living. Comments and questions are welcome and may be used in a column, along with the writer’s name and home community. Write Dr. Gridlock at The Washington Post, 1150 15th St. NW, Washington, D.C. 20071 or e-mail