Chris Ashker once could drive 20 to 30 mph on southbound Interstate 270 during his morning commute. It wasn't exactly highway speed, but at least traffic moved before backups began near Exit 11 to Montgomery Village Avenue.

That was four years ago. Now, Ashker said, southbound traffic comes to a halt two miles earlier, around Exit 15 to Germantown Road.

"I-270 has gotten ridiculously worse," said Ashker, 30, who commutes 80 miles round trip between his Germantown home and his job in Chantilly. "It's a dead stop at 6:30 in the morning."

The daily crush on I-270 and the Capital Beltway, Ashker said, is one of the most noticeable differences he encountered upon moving back to Montgomery County this year, after leaving in 2000.

Those four years constitute a blip in the minds of traffic engineers, who usually track traffic volumes over the long term, often by decades. But Ashker and others who navigate Montgomery daily say traffic now feels like it is growing so bad so fast that they feel the effects on a much more short-term basis, from one year to the next.

The Texas Transportation Institute has ranked the Washington region among the most traffic-clogged areas of the country for the past decade. Worse yet, the institute's annual rankings show the misery has only increased. In 2002, Washington-area drivers spent 67 hours stuck in traffic. That is nearly two days longer than in 1982.

But it doesn't take two decades to feel the pain. If it seems as if many Montgomery roads have gotten significantly more crowded in just the past few years, that is because they have, according to Maryland traffic statistics.

State engineers estimate that traffic volumes increase 2 to 2.5 percent each year, based on increases in population, licensed drivers and vehicle miles traveled, said David Buck, a spokesman for the Maryland State Highway Adminstration.

But the short-term increases on many Montgomery roads have been much greater, according to state figures. Some roads have seen a 50 to 100 percent jump in traffic in just a few years, particularly in the northern county and beyond. Development has taken off in Germantown, Damascus and Olney and in Frederick, Howard, Carroll and Washington counties.

From 1999 to last year, for example:

* The amount of traffic almost doubled on once-country roads such as Route 108 near the Howard County line, Germantown Road north of Clopper Road and Frederick Road (Route 355) north of Germantown Road.

* Developed and congested areas in the southern part of Montgomery, such as Bethesda-Chevy Chase, got more congested. The choke point on Connecticut Avenue (Route 185) south of East West Highway (Route 410) saw nearly 17,600 more vehicles daily -- up from 48,650 to 66,225.

* Traffic on parts of I-270, where the state is considering adding express toll lanes, grew by 20 percent. One section of the highway, near Exit 6 to Route 28, carried 260,000 vehicles, up from 217,000. What do 43,000 more vehicles every day look like? If that many Toyota Camrys were placed bumper to bumper, they would stretch from the White House to Philadelphia. Eight Hours of 'Rush'

On highways such as I-270 and the Beltway, which are at capacity during the morning and evening rush hours, squeezing more vehicles onto the same amount of pavement simply means the rush "hour" gets longer.

The rush on I-270 once extended from 6:30 to 9 a.m. and 3:30 to 6 p.m., Buck said. Now, he said, the combined crunch has spread from six hours into eight hours, lasting from 5:45 to 9:45 a.m. and from 2:45 to 7 p.m.

That is because motorists such as Ashker try to avoid the peaks by leaving earlier or later. Ashker said he works an earlier schedule so he can miss the rush on I-270 and the Beltway. He gets onto I-270 by 6:30 a.m. and hits the Beltway to head home by 4:30 p.m.

"I keep those hours for the traffic," Ashker said. "If I leave [work] a moment after 4:30 p.m., everything gets proportionally worse."

Even on a good afternoon, he said, "from the [Dulles] Toll Road to my house, it's pretty much stop and go."

Jeff Zyontz, chief of countywide planning for the Maryland National Capital Park and Planning Commission, said traffic flow works like water flow. Try to squeeze more water into a pipe that is full, he said, and the pressure increases against the pipe. When more vehicles try to squeeze onto a road that is full, he said, they, too, exert pressure in the form of rapidly reduced speeds.

"When you're near the margins of capacity," Zyontz said, "any growth changes speeds exponentially. . . . Any kind of interference becomes a major event. Before, the accident on the side of the road was a minor inconvenience. Now it's a major problem when you're nearing capacity."

Buck said the state is working to alleviate congestion on Montgomery roads. Gov. Robert L. Ehrlich Jr. (R) has called building an intercounty connector between Interstates 270 and 95 his top transportation priority, saying such a highway would ease crowding on smaller east-west roads through Montgomery.

The state also is spending tens of millions to improve congested intersections by adding turn lanes and extra through lanes, Buck said. Current projects include adding capacity on Connecticut Avenue at Veirs Mill Road, on Veirs Mill at Randolph and Aspen Hill roads and at several intersections on New Hampshire Avenue between Powder Mill Road and U.S. Route 29, Buck said. The state also is replacing stoplight intersections on Route 29 with interchanges, he said.

Richard Parsons, president of the Montgomery County Chamber of Commerce, said he believes motorists are feeling the effects of even "incremental" increases in traffic volumes because many roads have hit a "tipping point."

"For a while you can get around the bottlenecks by finding another route around it, but I think we've reached a point where there is no alternative capacity left," Parsons said. "There is no other cut-through route because everyone has discovered them all. We're just going to be stuck in line."

There is little disagreement on the cause: whopping growth.

Bryan Elie, 38, said he is not surprised that state figures show traffic volumes doubling on Germantown Road just north of Clopper. He moved to a newly built subdivision near the intersection two years ago. Elie said his commute down I-270 from Germantown to Chevy Chase has grown worse just in the past year, and he knows why southbound traffic on the highway backs up farther north in the mornings.

"There are probably double the number of homes around here in the last five years," Elie said. "They're continuing to build, and people keep moving in. I guess it's just the reality of suburbia."

Since 1993, Montgomery County has added 110,000 jobs and 42,000 housing units. Parsons said the increase in traffic, particularly in fast-growing areas such as Germantown, shouldn't surprise anyone. County officials preserved open space by planning for the area's population to grow along the I-270 corridor from Rockville to Clarksburg. The county followed through on development plans, he said, but failed to build key links in the transportation system, such as the planned Montrose Parkway and a transit line between Shady Grove and Clarksburg.

"These traffic volumes were projected years ago, and we planned a road and transit network to accommodate that, but we didn't build it," Parsons said. "So now we're seeing the natural consequences of that. Unfortunately, it's going to continue to get worse for a few years."

Lee Epstein of the Chesapeake Bay Foundation said the traffic boom on I-270 is testament to the negative effects of sprawl development, not too few roads being built.

"It should worry people," Epstein said. "We just can't accommodate the numbers that may be coming with the way the [transportation] system is currently configured. The way to deal with it is not to necessarily keep adding more lanes but to think about different ways of transporting people."

That should include much more transit, communities with more walking opportunities and denser development around transit stations rather than spreading development across cornfields, he said.

Judging by the Numbers

Just as striking as the increases in traffic volume are the decreases, according to the state's figures. The eastern portion of Montgomery's Beltway, between Rockville Pike (Route 355) and Colesville Road (Route 29), lost traffic from 1999 to last year -- 20,000 vehicles daily in some spots.

Buck said those decreases are probably related to a large construction project on that portion of the Beltway, in which the state replaced several overpass bridges. Motorists sat in daily backups as traffic squeezed between Jersey barriers, and state officials encouraged drivers to find ways around the construction, probably leading to the traffic decline.

Overall, however, "I wouldn't say we're losing any traffic on the Beltway," Buck said.

The traffic counts on the State Highway Administration's Web site, Buck said, come with some caveats. The state counts vehicles at 1,100 spots annually, he said. With a three-year rotation, the state provides traffic figures for a total of 3,300 spots.

During the year of an actual count, engineers measure traffic over a 48-hour period. Using computer calculations, they tally an "average daily count." In the two "off" years when a count isn't taken at a particular spot, Buck said, traffic analysts estimate increases or decreases based on several factors, including whether there is new development in the area.

Buck said the state does more detailed traffic counts before making any decisions about the need for road improvements in an area. However, he said, the average annual counts are useful as "very general tools to give you an idea of some general trends."

The trend in Montgomery, clearly, is up.

Chris Ashker of Germantown leaves for work before dawn to hit I-270 by 6:30.By 7 a.m., southbound traffic on Interstate 270 is backed up near the Route 28 overpass. The morning and evening rush combined is now eight hours long on I-270, from 5:45 to 9:45 a.m. and from 2:45 to 7 p.m. Bryan Elie of Germantown, shown with sons Garek, left, and Declan, has seen his commute to Chevy Chase worsen in just the past year.