There are signs that many area commuters are leaving their cars in the garage and taking transit or are carpooling because of record-high gas prices, though most Washington motorists appear unwilling, or unable, to forgo driving alone.
The amount of traffic on most of the region's major commuter routes last week was about the same as the week after Labor Day last year -- traditionally one of the busiest times on the highways as the return of vacationers, students and Congress cause traffic to surge to its usual, congested level.
Traffic should have increased from a year ago because of all the new people and businesses that have flocked to the region. Transportation experts suggested that the fact traffic has not risen substantially is evidence that people have altered their routines.
The numbers of drivers on Interstate 66 in Virginia and Route 50 in Maryland were down slightly, while traffic on Interstate 270 and the Beltway in both states increased slightly.
The numbers of vehicles using the carpool lanes on I-395 increased a little and traffic in the interstate's regular lanes was virtually the same.
Lon Anderson, director of public and government affairs at AAA Mid-Atlantic, said the leveling off in Virginia is especially surprising because the state "has certainly been growing. Loudoun is one of the fastest-growing counties in the country, and Northern Virginia hasn't added any mass transit."
Many more commuters are riding Metro. Subway ridership has jumped by about 50,000 people a day over the same week last year -- nearly an 8 percent increase that well outpaces the system's normal 2 percent to 3 percent annual growth.
Metro officials are so concerned about increases in ridership caused by high gas prices that they cautioned riders last week to expect rush-hour trains to be even more crammed than they have been. Officials also said that many users probably would have to wait for a train or two to pass before being able to board. Officials asked riders to travel on the "shoulders" of peak periods, when there is more room.
Metro officials also said that parking at subway stations would be tighter than usual and that many major bus routes in the city would strain to absorb new riders.
Representatives for commuter rail lines in Virginia and Maryland said the ridership numbers have risen moderately since last year, which they attributed to normal growth plus some new riders trying to escape high gas prices.
One of the starkest changes since gas prices started increasing dramatically is the number of people looking for carpools, which increased by at least 30 percent, according to the Metropolitan Washington Council of Governments.
"To have a 30 percent jump is just extraordinary," said Ronald F. Kirby, transportation planning director of the council, which coordinates carpools and encourages people to work from home.
Kirby noted that the number of people using a cost-of-commuting calculator on the council's carpool Web site -- www.commuterconnections.com -- has risen by 40 percent.
"Over the last 25 years, we've never seen anything like this in terms of a rapid run-up in the price of gasoline," Kirby said. "It's caused a bump in interest in our services like we've never seen before."
John Harbison has thought plenty over the years about giving up the comfort and convenience of driving to work alone. He toyed with carpooling a few years back and then tried the bus for a little while, but found both options less than inviting.
"It's always been a personal-space issue," Harbison said. "I've always been a little reluctant."
"I came in [Friday] morning and saw the Shell station was $3.39 and I said: 'Gee, I'm going to call Commuter Connections,' " he said. "I thought: Well, it's about time to start doing it."
Harbison said it costs $32 a week to fill up his Honda Civic and drive between Olney and the District -- more than twice what it used to cost. "I've got two kids in college and I'm looking for ways to save money," he said. "I think we all are."
Gas prices in the region are among the highest in the nation, averaging $3.20 a gallon Friday compared with the national average of $3.01. A month ago, gas in the area was $2.37 a gallon on average. A year ago, it was $1.85.
Despite all the changes, most commuters are driving by themselves and most area roads still have the usual backups and delays. AAA Mid-Atlantic's Anderson said that is partly because many commuters do not have other options.
"The fact is, a lot of people are hard-pressed, given how spread out we are here, to find any other way to get around other than the automobile," Anderson said. "The people out there pretty much have to be out there."
Some who are trying to cut their costs said they are not having any success. Lauren Greenwell said she has been unable to find a third person to share a carpool between Fair Lakes and the District. She switches off weeks with another driver and, with gas prices being what they are, they would like to add someone they only have to drive every third week.
Greenwell said that would cut the cost of filling her Honda Accord from $100 a month to about $65.
"A lot of people are not willing to drive into D.C.," she said. "They just want a ride." So she and her fellow carpooler drive on, trading off weeks.
"Gas prices are crazy," Greenwell said. "It hurts. It really hurts to fill up."