No mention of congestion pricing is to be found in Mayor Bloomberg’s second-term agenda, which has led several advocates of the approach to abandon what is considered one of the most radical traffic reforms possible for the city.

Congestion pricing, successfully implemented in London since 2003, works by charging drivers in congested zones during peak hours. In Manhattan, these zones would include busy streets leading to Midtown, where traffic during the morning and afternoon rush hours is 50% over capacity, according to the New York Metropolitan Council of Transportation.

In light of the mayor’s lack of support, a key advocate of the project, Transportation Alternatives, is “taking a step back” and addressing other issues, including the way the city deals with parking and buses and the methods used to analyze traffic, the group’s executive director, Paul Steely White, said. Mr. Bloomberg has said congestion pricing won’t work in New York City because of the way the city is structured.

The group that originally led the campaign for congestion pricing, Partnership for New York City, is confident the city will listen if it makes a persuasive case. Its report detailing desired traffic changes will be finished in the spring.

“We’re looking at it from the angle of what’s good for the New York City economy,” the partnership’s director and CEO, Kathryn Wylde, said. She said the other groups aren’t so much backing off as making clear what their priorities are.

About $6.8 billion a year is lost in productivity because of time wasted in traffic, she said. Many of the transportation advocacy groups said they are gearing up for smaller initiatives to improve traffic conditions in the city, rather than attempting to impose congestion pricing from the top down on city residents.

“Congestion pricing may be a controversial topic,” the director of the Straphanger’s Campaign, Gene Russianoff, said. “But, the intermediate steps are not: speed bumps, preventing trucks from careening down your street, higher meter parking for commercial interests in Midtown.”

Citizens for New York City, a group headed by a former congressman of Pennsylvania, Peter Kostmayer, is leading the grassroots campaign for “traffic relief.” The group has created a charter calling for citywide traffic volume to be reduced 15% by 2009. It is pushing for five changes by the city in addressing traffic, among them congestion pricing. Seventy-six neighborhood organizations, including block associations and groups that organize public gardens, have signed the charter so far.

Transportation Alternatives decided to change strategy after reviewing the way the London program evolved, Mr. White said. New York City calculates “street performance” by the amount of cars passing through an intersection in a period of time. The group wants New York to analyze performance by what kind of cars are moving through the city. If a street, for instance, had a large percentage of higher occupancy vehicles like buses, that could be a new marker of success, he said. Such a step was taken by London before it attempted to implement congestion pricing.

There is “a growing consensus that New York is not measuring transportation performance in a meaningful way,” Mr. White said.

An informal adviser to Mr. Bloomberg and professor at New York University’s Wagner School of Public Service, Mitchell Moss, said the flawed idea of congestion pricing rested on a Manhattan-centric view of New York City.

“They do not understand or appreciate that there is no mass transit in certain parts of Queens, Brooklyn, Staten Island, and the Bronx,” he said. “Congestion pricing advocates really have adopted a strategy based on the experience of London, which like so many British practices is inapplicable to New York City.”