ATLANTA , Georgia ( CNN ) -- U.S. cities are racing to cope with ever-increasing demand on public transportation as gas prices remain at record levels . High gas prices in recent months have had a considerable impact on commuters using public transportation , statistics show . Even regions that have traditionally resisted giving up cars and have limited access to mass transit are reporting a surge in public transportation use . From trains and trolleys to subways and buses , the growth encompasses all modes of travel , according to the American Public Transportation Association , a Washington D.C.-based industry group . Cities are using a variety of measures to meet that demand , according to an informal APTA survey of some transit systems . For example , the Massachusetts Bay Transportation Authority , which is currently operating at capacity during peak periods , ordered more subway cars , buses and coaches for its commuter rail . In North Carolina , the Charlotte Area Transit System has increased the frequency of light rail service on the weekends , ordered new buses and is taking a look at low-performing routes to cut down on costs . And the Southeastern Pennsylvania Transportation Authority , which serves Philadelphia and has seen about 20,000 new daily customers since last July , has ordered 400 new hybrid buses and 120 new rail cars . Other measures being used or considered by transit systems include changing schedules to increase frequency of buses and trains , creating bus-only lanes and taking out seats on trains to make more room for commuters . 'The paradox of public transportation ' While the rise in ridership has been a relatively easy adjustment for some systems , others are facing difficulties in meeting operating costs , which hampers their ability to ramp up service or maintain normal levels . Cal Marsella , the head of Denver , Colorado 's transit system , calls it the `` paradox of public transportation . '' Denver 's system , like many U.S. cities , is partly funded by revenues from sales taxes . As consumers spend less because of high fuel costs and a sour economy , the city earns less revenue . Consequently , funding for the transit system is decreasing just when their operating costs are higher than ever before . `` Just when our demand is highest , our ability to provide is being undermined by the whole crunch , '' Marsella said . `` The last thing we want to do is curtail service but there is not a lot you can do when revenues are down and fuel prices are up . '' The Denver Regional Transit District , however , saw the high prices coming and was able to lock in the price of diesel fuel earlier this year at $ 3.20 a gallon -- a price far cheaper than what the market is right now . That contract expires at the end of this year . See a map of gas prices across the country » . Marsella is pessimistic prices will drop much by the end of the year . `` I 'm budgeting next year for $ 4.55 a gallon , '' he said . `` Everybody is hurting , and I have real concerns about our ability to sustain services and maintain infrastructure . '' A sharp rise in ridership . Americans used public transportation in record numbers the first three months of this year , according to the APTA . They took 2.6 billion trips on public transportation during that period , an increase of 85 million more trips compared with the same period last year . Meanwhile , the number behind the wheel dropped . Americans drove 1.4 billion fewer highway miles from April 2007 through April 2008 , according to figures released by the Department of Transportation in June . The numbers represented the sixth consecutive monthly drop . In some places , the growing embrace of public transportation has been an ongoing trend for the past few years , reflecting a steady and gradual change in commuter behavior . iReport : Show us your commute . For instance , ridership increased during a period of high fuel prices from 2005 through 2006 in Tulsa , but did not decline after fuel prices went back down , said Cynthia Stabb of Tulsa Transit . `` Once people get a chance to try public transit and they find it works for them , they stick with it , '' she said via e-mail . Asked about the current high levels , she responded , `` We believe the demand is here to stay . '' Turning point ? Some observers such as Dr. Robert Lang , an expert on urban affairs and planning at Virginia Tech University , say the gas crunch could be a turning point in perceptions of public transportation and how cities plan development . Consumers are beginning to believe the high prices are a result of structural changes in the global economy , not the result of a single event like Hurricane Katrina , which produced a period of high fuel prices earlier this decade , Lang said . That change in perception is providing more momentum for some cities that were already moving away from six-lane highways and suburbs dozens of miles apart , to a series of urban centers connected by light rail and other mass transit systems . He cited cities like Denver and Phoenix , Arizona , where residents , motivated by traffic frustrations and the promise of economic development , approved massive transportation projects during the past few years despite the costs to their pocketbooks . Marsella said Denver 's suburban and exurban commuters were as enthusiastic as its urban residents in approving the multibillion dollar project in 2004 . `` People want to drive their cars a mile or two to a park-and-ride , and then take the rail in on the most congested part of the trip , '' he said . Other cities , like Atlanta , Georgia , for instance , are struggling to make the pivot . Often cited in discussions about urban sprawl , Atlanta has been bedeviled for years by a lack of consensus among city and regional leaders on the need to expand its transit system . `` Some of it is just the fear of change , '' Atlanta Mayor Shirley Franklin said . `` People acted as if transit was a dirty word and the only thing that would be successful in Atlanta would be to build more roads , but we can see from the congestion that you need an integrated transport system . '' Watch Mayor Franklin talk about Atlanta 's transit system » . `` Unfortunately , there 's no quick answer for the problems that we have . '' Roads , and the cars on them , will not likely disappear anytime soon , Lang said . `` We 're a settler nation . And people had to get moving to do that , '' he said . `` There 's something deep within the American psyche about the freedom of movement . '' But the current environment may lead to a future where hybrid cars coexist with denser transit systems . `` 2007 , for all we know , might be the peak use of gas in the United States , '' he said . CNN 's Mike Senzon and Jarrett Bellini contributed to this report .
Statistics suggest Americans are driving less and using mass transit more . Comment: They are hampered by high operating costs , spurred by high fuel prices . iReport : Show us your commute .