Traffic congestion like this is all too familiar to veterans of the Capital Beltway commute. (Photo by Linda Davidson/The Washington Post)

Terrible Traffic Tuesday,” a coinage of AAA Mid-Atlantic’s Lon Anderson, who retired this summer, describes the first commuting day after Labor Day, when the benefits of the summer lull finally disappear.

Commuters in the D.C. region already have noticed that they are sharing the trip with more travelers than were present during July and August. A final big blow occurs this week as many Virginia students return to their public schools.

The spot annoyance of Terrible Traffic Tuesday and the lingering pain we call September Shock are real things, even though individual travelers don’t experience them in exactly the same way or at exactly the same time because of the variety of ways people get to work in this complex region.

Ben Hampton and Wenjing Pu, who are on the Transportation Planning Board staff at the Metropolitan Washington Council of Governments, explained what makes us so collectively uncomfortable when summer ends: The total increase in traffic volume in September isn’t so great, but people now concentrate their trips into the narrow peak periods during the mornings and afternoons. School start times are one very big factor in this, as parents lose the scheduling flexibility they had during the summer.

Some of you would have noticed no effect of this during this morning’s commute, while others were stuck with especially difficult drives. Take, for example, the morning commute on the northern arc of the Capital Beltway in Maryland on Tuesday morning. That heavily traveled route became extra slow when several lanes on the outer loop were closed following a crash near Georgia Avenue. When drivers lose that summertime flexibility and concentrate their travels in narrower windows of time, the bad effects of lane closings are compounded.

The online traffic maps, which display routes in a green-to-red color code as they move from okay to very slow, were showing more red on Tuesday morning than they did on most mornings in August. But here again, results varied. Portions of I-66 and I-395 that often are slow after Labor Day offered relatively smooth trips even after 8 a.m.

Meanwhile, Metrorail had its usual share of delays, including Red Line delays caused by a track problem outside Bethesda. But the effects of these delays worsen as commuters return to their fall travel patterns.

Sometimes, seasonal overlaps contribute to the crowding. The Boys of Summer probably will have an effect on the Tuesday and Wednesday evening Metrorail commutes. The Nationals play the first-place Mets at 7:05 p.m. in Nationals Park on Tuesday and Wednesday. The well-attended games will add to crowding on the Green Line and at Metrorail’s transfer stations.

What can you do about the various forms of September Shock, besides be patient? Here are a few tips.

Departure times. Start your commute earlier or later. You might have an easier time applying this to the afternoon commute. In September, the morning’s peak periods tend to spread out over a longer time before and after 9 a.m. You might need to make a big adjustment. The afternoon peak, about 6 p.m., also spreads, but not as much.

Telecommute. If you can pick a day to telecommute, consider Tuesday, Wednesday or Thursday. Those tend to be the peak days for traffic.

Metro. Ridership tends to increase in September and October before hitting another lull around the November-December holidays. Riders will see more of the new eight-car trains in service, but they still will endure uncomfortable crowding during rush hours. When I stake out a station and just watch trains go by, I notice that the last two cars of an eight-car train still tend to be much less crowded than the front six.

Transit center. The long-delayed opening of the Silver Spring Transit Center, now scheduled for Sept. 20, will unsettle downtown traffic patterns, but the new transit hub will finally remove many bus stops from nearby streets.

Driving. “Driving in heavy traffic demands patience, perseverance and special skills,” said AAA’s John B. Townsend said. Resist the temptation to glance down at an electronic device when stuck in a traffic backup, look far ahead to make sure you are alert to changing traffic conditions and avoid sudden moves.

Road work. This fall, a year-and-a-half-long resurfacing project is scheduled to begin on heavily traveled Route 50, between Lottsford Vista Road and the border of Anne Arundel and Prince George’s counties.

The District Department of Transportation recently began an 18-month improvement project on Minnesota Avenue NE that will restrict the travel lanes — and affect Metrobus routes — to make room for the work zones.

The Virginia Department of Transportation is beginning a major makeover for the interchange at Interstate 66 and Route 15 in Haymarket.

The ramp between the Interstate 395 HOV lanes and Seminary Road by the Mark Center is scheduled to open in late September. But the most interesting traffic development of the fall is likely to occur when VDOT lights up its Active Traffic Management system on I-66. It’s a network of electronic monitors, alerts and lane controls meant to help drivers make smarter travel decisions and thus alleviate congestion.