Along the DART Red Line north of Dallas, commuters are parking at big box stores or along curbs up to a half-mile from the station.

In Tarrant County, Trinity Railway Express riders are bicycling to train stations to avoid parking headaches, and transit officials are paving over landscaping to squeeze in extra parking spots.

“If you’re not here early, you’ll have trouble,” said Rob Roselle of Murphy, who catches the Red Line at the Bush Turnpike station in Richardson.

More park-and-ride lots in the area are filling to the bursting point. The packed lots are a symbol of transition for a region long wedded to the automobile that now is embracing rail and buses in larger numbers.

Commuters and transit officials say crowds have risen sharply since gas prices began rising. DART and other agencies, meanwhile, hope to alleviate the problem by building more lots and taking more immediate steps.

Interest in transit has spiked before, most notably after gas prices ballooned following hurricanes Katrina and Rita in 2005. But many believe the current wave will not subside soon.

DART rail use on weekdays was up 9 percent in May, recent data show. Boardings on the Tarrant County side of the TRE were up a record 22 percent in June. Bus use also is rising.

JIM MAHONEY/DMN

Security officer Hizekel Fichew places a parking advisory on a windshield of a car parked illegally near the DART Bush Turnpike Station.

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In fact, ridership is increasing sharply across the nation, leading to crowds at park-and-ride lots elsewhere.

Lots are packed in Houston, Phoenix and communities in the Pacific Northwest. The Tri-Rail system in South Florida saw ridership skyrocket 43 percent in June alone, fueling problems there, a spokesman said. Some parking lots in San Diego are holding more than twice as many cars as last year.

Likewise, increase transit use here has put a premium on parking. That’s particularly true along DART rail, where more than a third of all passengers on an average day use park-and-ride lots.

The worst crunches appear to be at stations near the end of the line, such as at Parker Road in Plano and the Bush Turnpike on DART’s Red Line. Both serve as outposts for motorists driving from far-flung exurbs.

Transit lots in Garland, Glenn Heights, Hurst, Richland Hills and parts of Dallas also are at or nearing capacity.

“We’re overflowing right now,” Richland Hills Mayor David Ragan said.

Transit planners figured they could create about 20 new spaces in Richland Hills by paving over landscaping there. A few have taken to biking to the station.

In Plano, overcrowded lots have forced riders to seek out makeshift alternatives, such as back streets and grassy areas. Scores of resourceful commuters at Bush Turnpike are parking almost a half-mile away, behind a Fry’s Electronics store on Plano Parkway.

Warren Fortson, a Fry’s supervisor, said commuters began appearing several months ago when gas prices started climbing. He said the store has generally accommodated them but that management will act if the trend begins disrupting business.

Julia Murray, an executive assistant at Texas Instruments in Dallas, said her company allows workers to arrive between 6 a.m. and 9 a.m.

Ms. Murray, who boards DART around 6 a.m., takes full advantage of the flexibility. “If you get here at eight o’clock, it’s just packed,” she said.

Jay Kline, DART’s interim vice president for planning and development, said the agency is working to provide relief.

DART has accelerated plans to build new lots at Parker Road and Bush Turnpike and at an express bus terminal at Glenn Heights. The estimated $6 million effort, which will finish by spring, will add more than 1,000 spaces to DART’s current inventory of 18,000.

DART also may install signs to direct commuters to open lots and reconfigure bus routes to better feed rail stations, Mr. Kline said.

In the long term, transit officials say they want to encourage riders to ditch their cars altogether. They support the construction of housing and retail near rail stations.

The TRE is taking similar approaches. In addition, efforts are underway to purchase land and build new lots along the TRE line, said Joan Hunter, a spokeswoman for the Fort Worth Transportation Authority.

DART also is looking into supplementing free parking with “premium” lots close to some stations that would be available to carpoolers, vanpoolers and those who elect to pay a fee, Mr. Kline said.

The improvements cannot come soon enough. Faye Moses-Wilkins, a member of DART’s board of directors, said she has received many phone calls from commuters pleading for parking help.

“The influx of ridership hit us almost overnight,” she said. “We can’t build parking lots overnight.”

Virginia Miller, a spokeswoman for the Washington, D.C.-based American Public Transportation Association, said the crowds highlight the expansion needs of transit systems here and beyond.

“Taking public transportation is the quickest way to beat high gas prices and save money,” she said. “But it’s a double-edged sword.”

With park-and-ride lots filling up throughout the area, DART is embarking on several initiatives to alleviate overcrowding. The measures include:

•Building new parking spaces at Parker Road, Bush Turnpike and Glenn Heights stations.

•Using electronic signs to direct commuters to open lots.

•Encouraging commuters to take buses, carpools to rail stations.

•Setting up satellite lots and bike racks at the busiest stations.