It's one of those roiling rituals of summer, more infuriating than sunburn, more inevitable than jellyfish stings: the beach-bound backups.

And just when it seemed the tide of traffic couldn't rise any higher, beachgoers got what they wished for most. Sunshine. Endless sunshine. So many weekends of rainless, flawless, grade-A guaranteed sunshine that the highways have been heavier perhaps than any other summer in recent years.

"With the weather as nice as it's been almost every weekend, we've had some pretty significant backups," said David Buck, spokesman for the Maryland State Highway Administration. "The weather this summer made it a whole different level."

Saturday mornings are bad. Friday evenings are bad. Try beating the crush, and you discover Friday afternoons can be even worse.

Evening rush hour, which once started at about 3 p.m. on summer Fridays, now follows hard on the heels of morning rush hour, beginning as early as 1 p.m. as the work force races to swap dress suits for swimsuits, said Lucy Caldwell, spokeswoman for the Virginia State Police.

Head east toward the Maryland shore along Route 50, and the traffic slows at the Severn River Bridge and the Chesapeake Bay Bridge tolls, and then again at the Route 301 split and yet again at the Route 404 split toward the Delaware beaches at Rehoboth, Dewey and Bethany.

During the final stretch along two-lane Route 90, with Ocean City looming ahead like a mirage, cars can easily back up for five miles, according to Pete Piringer of the Maryland State Police.

But wait till you head home. That sense of inner peace born of warm sand and the soft lullaby of the surf quickly dissipates amid the tie-ups, some exceeding 10 miles, that await motorists at the Route 50-301 and Route 50-404 interchanges.

Late yesterday afternoon, Jack Gray and his son Keith were standing at the Bay Bridge Texaco peering into the 98-degree haze rising off the traffic on Route 50 looking for the second car in their beach caravan.

The Grays, from Berryville, Va., between Loudoun County and Winchester, usually leave for their family fishing expeditions to Chincoteague, Va., at 1 o'clock Saturday morning. Their room opened up early, so they chanced the afternoon traffic. But it swallowed the rest of the family. Gray lost track of his wife and mother somewhere around Tysons Corner.

"Coming back," he said, "we'll leave at 3 or 4 Monday morning."

At the peak, about 4,000 cars an hour cross the Bay Bridge, Buck said. A decade ago, a mere 3,000 cars was considered a massive rush and the maximum the roads could accommodate.

But then, Maryland widened Route 50 from four to six lanes and removed many traffic signals. Now, a Washington traveler encounters the first light about 13 miles east of the Bay Bridge.

"It's tremendously better than it was 10 years ago," said Steve Kuciemba of the SmarTraveler traffic information service.

For those heading south from the Washington area toward Virginia Beach or the Outer Banks of North Carolina, congestion is heavy along Interstate 95 until the Fredericksburg area, where commuter traffic finally ebbs and resort-bound travelers find some relief, Caldwell said.

"I have nothing good to say about traffic right now," said Richard Dellavalle, who frequents the Outer Banks. He paused late yesterday afternoon at the Dale City rest stop after more than an hour of driving from his Rockville home. "It's just Northern Virginia. It doesn't matter when you leave, it'll be like this until 10 minutes north of Richmond."

Southbound I-95 had been bumper-to-bumper from Potomac Mills since 2:30 p.m. Even the car-pool lanes were crammed.

"Hopefully, it'll be relaxing once we get there," Dellavalle said.

Farther to the south, the tunnels in the Tidewater area are regular bottlenecks, and traffic in Virginia Beach backs up along the expressway. Indeed, Virginia Beach has grown so congested that the city banned most motorists from the oceanfront area during the Fourth of July weekend, busing in beachgoers from remote locations.

One major irritant to weekend traffic was removed earlier this month after the Virginia Department of Transportation decided to remove construction barriers and other equipment from the stretch of I-95 near Emporia close to the North Carolina line.

As part of an effort to rebuild 13 miles of the interstate, among the few remaining original stretches of the highway, the state had restricted it to one lane in each direction over the last two summers. But after mounting public exasperation with jams of up to 10 miles, VDOT delayed the scheduled completion of the project until late this year and ordered the roadway to be cleared during summer weekends.

But frustration remains high along Route 168 in Chesapeake, where a torrent of travelers bound for the Outer Banks must funnel through a two-lane country road before it opens up into four lanes over the North Carolina line.

Staff writers Christina A. Samuels and Jefferson Morley contributed to this report.