The region's commuters suffered through one of the worst mornings in months yesterday as a steady rain contributed to dozens of crashes and a slow response by D.C. police exacerbated the everyday challenge of heavy traffic.

In Northern Virginia, state police reported 22 traffic accidents during the morning--more than the total during Hurricane Floyd last week. But it was a pair of accidents on the 14th Street Bridge and on the Capital Beltway in Bethesda, both during the start of the rush, that left traffic reeling.

"It just went haywire for the rest of the morning. It was horrible, just horrible," said Steve Kuciemba, of the SmarTraveler traffic information service. "The traffic volume has increased so much in the last couple of years, whenever you get an unusually bad accident or bad weather, it can turn the whole region into total gridlock."

D.C. police decided yesterday afternoon to examine why it took "an inordinate amount of time" for officers to respond to an accident about 7 a.m. on the 14th Street Bridge, according to spokesman Sgt. Joe Gentile.

By the time the disabled vehicle was cleared about two hours later, northbound traffic on the Shirley Highway had backed up from the Potomac River to Dale City, nearly 26 miles of solid congestion. Gentile said details of the incident remain sketchy but promised the department would "take appropriate action" after it determines who was responsible for the sluggish response by police.

"It was an absolute parking lot," said Bonnie O'Neill, of Arlington, whose usual 20-minute commute downtown across the 14th Street Bridge was disrupted. After trying unsuccessfully to enter Interstate 395 at two places, she opted for the Roosevelt Bridge. "It took an hour and 35 minutes to get to 17th and L. It was a nightmare." She said she was very angry, "especially when I heard they left the disabled vehicle sitting there for two hours. It's getting ridiculous."

The accident on the bridge was the second blow in a one-two punch that staggered rush-hour travel. About 6:30 a.m., the driver of a tractor-trailer headed east on the Beltway's inner loop near Old Georgetown Road lost control and the rig smashed into a guardrail before rebounding onto the highway, police said. The truck was struck by two cars and another tractor-trailer. Though no one was killed, the crash closed all eastbound lanes, backing up traffic as far as the American Legion Bridge.

The real impact, however, was felt in the westbound lanes of the outer loop, typically heavier during the morning commute. As rubberneckers slowed to survey the crash, traffic backed up more than 25 miles along the Beltway and Interstate 95 as far as Route 175 in Howard County, according to Maryland State Police spokesman Pete Piringer. On the Beltway, cars were tied up for more than 13 miles, to College Park. The Beltway congestion and rain also aggravated usual rush-hour delays on I-270, backing up southbound traffic for about 13 miles.

"It was terrible," said Sandi Dobson, of the Maryland State Highway Administration.

Police needed about two hours to clear the jackknifed tractor-trailer from the Beltway because authorities dispatched a sand truck to the scene before removing the wreckage because of concerns about a possible fuel spill, Dobson said. The highway remained congested until nearly noon.

"This morning's commute was a nightmare for everyone," said Virginia State Police spokesman Lucy Caldwell. "We haven't had a lot of rainy mornings. It wasn't as fresh in people's minds how to adjust to these wet roads."

The homebound rush hour also was no treat for many commuters. Accidents snarled traffic in spots including I-66 between Route 123 and Nutley Street in the Vienna area, Virginia State police said. On the George Washington Parkway near Turkey Run Park, a tree fell on a 1996 Jeep Cherokee around 5:15 p.m. The driver was not injured, but the road was blocked for about 20 minutes, causing traffic to back up for several miles, said U.S. Park Police officer Ken Fornshill.

"It was raining hard, people were traveling slower, visibility was poor," said Virginia State Police's Caldwell. "It was not as dramatic as it was this morning."