Despite public transit ridership at its highest levels since the birth of the interstate highway system, nearly 90 percent of transit agencies in the United States have been forced to raise fares or cut service in the past year, a new report says.

The report, "Stranded at the Station: The Impact of the Financial Crisis in Public Transportation," was issued last week by Transportation for America, a nationwide coalition of hundreds of housing, business, environment, public health, transportation, government and development groups and officials.

It called the situation "an epidemic that did not have to happen" and urged greater federal support for transit.

State and local budget problems have forced agencies across the United States to cut service, raise fares and lay off workers despite a surge in demand.

Last year, Americans took 10.7 billion trips on public transit, the most since 1956, the year Congress approved construction of the interstate highway system, the report said.

Transit reduces congestion, stimulates development, cuts pollution and gives job options and mobility to those who can't afford or are unable to drive. "With both the demand and the payoff so high, now would seem to be the time to build on this success and expand transit options, yet the opposite is happening," the report said.

David Goldberg, communications director for Transportation for America, said multiple factors should fuel continuing growth of public transit -- including a population that is increasing and aging, increased urbanization and environmental concerns.

"All things point to an increased need for a reliable, robust, appealing set of transit options," he said. But "there's certainly a risk that people who have been lured to transit ... will instead learn that it's getting more expensive and less dependable and not use it."

"It's very troubling," Port Authority CEO Steve Bland said of the nationwide wave of fare increases and service cuts. "You have to take advantage of opportunities when you have them."

Port Authority is expected to raise its $2 base fare by up to 25 cents, effective in January. An announcement of the exact size and nature of the increase is expected by the end of this month.

The authority also is finishing a complete overhaul of service that it describes as a realignment to improve efficiency rather than a reduction.

Mr. Bland said the agency has not been hit as hard with revenue declines as many other big transit providers, but it faces the challenge of flat state and county funding in coming years. That accounts for 60 percent of the authority's revenue.

Budget projections, which Mr. Bland cautioned are subject to fluctuation, show a $29 million deficit in 2010-11 and $45 million the following year.

Transportation for America said only 18 percent of current federal transportation spending goes to public transit, with 82 percent devoted to highways and bridges.

Moreover, local governments typically are required to put up a bigger share of matching funds than for highway and bridge money.

"Existing federal policy is out of date and out of touch with the reality of public transportation's growing importance to Americans and their communities," the group said.

It said the upcoming debate in Congress over a new six-year transportation bill is "a once-in-a-generation opportunity to create the safe, clean and smart transportation system necessary to ensure all Americans have the options they need to succeed in today's economy and to move our country forward."

Federal spending on public transit would be more than doubled under a version of the bill submitted by U.S. Rep. James L. Oberstar, D-Minn., chairman of the House Transportation and Infrastructure Committee.

But Mr. Goldberg said the group is concerned about a proposal, backed by the Obama administration and Senate leaders, to delay consideration of the bill for 18 months.

"The prospect of putting the whole discussion about what we need to do about transportation into hibernation for 18 months is a little disquieting to us," he said.