Bobo radical: Paul Steely White in the Chelsea offices of Transportation Alternatives. 

“I notice when I am riding that I run a lot of red lights,” the 6-foot-2 Paul Steely White shouted over his shoulder. “The way I think of it, it is more important to watch out for pedestrians than lights, because there are a lot of jaywalkers in New York.”

Mr. White, the executive director of Transportation Alternatives, a pedestrian and bike advocacy group, was loping down Mott Street in Soho in a cold January drizzle on a single-speed 1971 Schwinn, weaving in between cars trying to find their way onto the Williamsburg Bridge—a bakery van pulling suddenly over to the curb, a truck snorting forth.

The 36-year-old Mr. White was on his way to a community-board meeting in Park Slope to ask its support for Intro 199, a City Council bill that would require the city to track traffic patterns around New York and set goals for reducing auto use.

It is, he explained, a necessary step toward any sort of congestion pricing—the system, devised in London, whereby drivers would pay for the privilege of driving into the central business districts of New York City.

(The fee wouldn’t be collected at booths like tolls, but rather ­indirectly, through EZ-Pass trans­ponders or through monthly bills that would be sent to drivers who had tripped a camera taking photographs of license plates.)

Once the domain of traffic nerds, congestion pricing has taken hold here recently like never before. Both the Partnership for New York City, a prominent group of business executives, and the Manhattan Institute, the conservative think tank, endorsed or re-endorsed it in December, joining a list of longstanding proponents such as the Regional Plan Association.

Mr. White represents the left flank, then, of a set of strange bedfellows. Founded by radical bicyclists in the 1970’s, Transportation Alternatives comes across as a sort of alterna-elite group of forward-thinking urban planners.

About half of its 5,500 members are from Manhattan and brownstone Brooklyn, and its 18 full- and part-time employees are generally white, well-educated twentysomethings who ride their bikes to work. Many of its largest donors are Wall Street types, and its largest individual funder is Mark Gorton, the high-tech entrepreneur who founded LimeWire. To them, Mr. White says, “Biking is the new golf.”

But T.A., as it’s called, has long tried to project itself as a generally pro-person, anti-traffic group. The city Department of Transportation ended up copying Safe Routes to Schools, a program established by Mr. White’s predecessor, John Kaehny, which seeks improvements to streets near schools. A similar program, Safe Routes for Seniors, is next in line for adoption, Mr. White hopes.

And the group regularly submits suggestions for traffic improvements throughout the city, sponsors bike rides, and gives away helmets in poor neighborhoods.

The potential constituency for this tiny, million-dollar-a-year organization headquartered in a Chelsea loft is quite large. Everybody has a gripe about traffic, after all, and it’s only going to get worse.

“If you go up to the South Bronx, they really love T.A. there,” said Aaron Naparstek, a former T.A. employee who now edits Streetsblog, a Web site promoting the “livable streets” movement. “They used to think, ‘This is the way New York City is.’ And then this young kid from T.A., with maybe an Ivy League degree, comes in and says there’s a whole set of traffic-calming tools that you can use to change that.”

THERE TO BRIDGE THE WORLDS OF WALL STREET and the South Bronx, lefty advocacy and Republican-controlled City Hall, is Paul Steely White, a blond-haired, blue-eyed surfer dude who has a touch of the aristocrat about him. He uses his middle name a lot, because it was his grandfather’s and it makes it easier for people to Google him, he said; and, in casual conversation, he favors old-fashioned words like “alighting” and “thoroughfares.” Somehow, it works.

“He understands what our world is and brings a real constituency with him,” said Manhattan Borough President Scott Stringer. “When he came to us about closing Central Park to traffic, he had gathered thousands of signatures from people and politicians and laid out all of the arguments.”

Born in Utah to Mormon parents (they soon left the church and divorced), Mr. White was raised in New Orleans and in Rockford, Ill. He came to New York City in 1997 after graduate school in environmental science to direct overseas projects at the Institute for Transportation and Development Policy, an organization allied with Transportation Alternatives. When T.A. was looking to replace Mr. Kaehny, who left to become a consultant to nonprofits, Mr. White already was a known entity whose experience dealing with foreign governments proved his ability to present and persuade.

The idea of charging people to come into Manhattan had been around for a long time before Mr. White came onto the scene.

Mayor John Lindsay proposed tolls on the East River bridges in the 1970’s. In the 1990’s, the then president of the Partnership for New York City, Robert Kiley, mentioned it. Mayor Bloomberg floated the idea early in his term. In each case, the plan failed because it came across as a tax on the outer boroughs as opposed to a traffic solution.

Then, four years ago, London instituted its congestion-pricing system. Traffic has fallen by one-fifth, and the revenue gets pumped back into the mass-transit system.

London has demonstrated to business leaders who traveled there the quality-of-life benefits of traffic reduction, who in turn have tapped into New York’s fear of losing ground in the battle for global commerce. In December, the Partnership for New York City released a report stating that traffic congestion was costing New York City businesses and consumers $13 billion annually.

“The common ground is that traffic creates a whole series of problems for the city from the standpoint of business,” said Kathryn Wylde, Mr. Kiley’s successor at the partnership. “The cost and inefficiency created by the loss of mobility is a huge expense and means the loss of revenue. When people don’t have easy access to business locations, when employees are delayed in getting to appointments, when you have to leave work an hour early to get to the airport, those costs are all absorbed by business and are often passed on to consumers.”

Instituting congestion pricing in New York will be a lot harder than in London, where it took but 18 months. London has control over its mass-transit system, while here the Mayor would have to spend his political capital to get it passed, only to then see the revenue flow to the Metropolitan Transportation Authority, a state entity.

Any proposal would need support from the State Legislature and the City Council, where outer-borough politicians play a decisive role.

“Ultimately, the city of New York has to be a livable city for all New Yorkers,” said Walter McCaffrey, a former Queens City Council member who is the director of an organization called Keep New York City Congestion Tax Free, founded by the Queens Chamber of Commerce last year. “If you have a system in place where the rich would no longer have to contend with other vehicles blocking their vehicles, that would end traffic congestion. They’ve tried to make it seem like if you are not in favor of congestion pricing, then you have given up on the problem of congestion. But that’s not true.”

Mayor Bloomberg has been cool to the idea, but his aides have said that congestion pricing is still under consideration for the N.Y.C. 2030 report—a set of policy recommendations to make the city more environmentally sustainable, due out in March.

“It’s very clear that we have to begin to shift more cars, more people who are coming into this city for whatever reason, to mass transit,” said Deputy Mayor Daniel Doctoroff, Mr. Bloomberg’s right hand on development, speaking to The Observer on Jan. 30. “That requires both getting them off of the roads, to the extent that it’s possible, but it also requires significant investments in expanding the mass-transit system.”

THE COMMUNITY BOARD IN PARK SLOPE ended up refusing to endorse Intro 199, complaining that it was too much “nibbling.”

Afterward, Mr. White headed to a barbecue joint close by, which also happens to be near his home. Wearing burgundy clogs, jeans and a brown canvas jacket that somehow passed as a sport coat, Mr. White launched into his vision of congestion pricing.

The point would be to devise a system that would make the public see it differently than it saw East River tolls. So, for one thing, he says, it would not just be weekday traffic in Manhattan south of 60th Street that would be charged a fee, but cars in downtown Brooklyn and in Long Island City as well.

And the charge—somewhere around $6 or $8 daily—would somehow fluctuate, depending on how congested the city is on any one day.

“Any solution that is brought to bear on New York’s traffic problem, the pain has to be applied equitably and geographically. Otherwise, it is going to fall victim to the borough-versus-borough thing, where it will just be perceived as a craven tax ploy,” Mr. White said.

As he went on, it became clear that Mr. White didn’t think congestion pricing would become policy any time soon—maybe under Mayor Bloomberg, more likely under his successor. T.A. will use that time to build the case for congestion pricing, and to introduce a list of initiatives that will reduce traffic.

As his argument unfolded, Mr. White turned out to be not just a guy concerned with painting bike lanes on streets, but someone concerned with the very nature of civilization itself.

“If you look at how much public space there is in cities—you know, the space between buildings—how is that space programmed? What’s it used for? Is it used for the benefit of everyone living in the city, or is it used for a relative minority, their parking or driving?

“If you think about cities,” he continued, “like why did they exist in the first place, they existed because of transportation—concentrating the destinations, services, goods, ideas. That’s what makes New York so great—right?—is it’s density.

“But then you have the lowest-density mode of transportation taking up so much of this public space. So few cities have been minimizing automobile use, but now cities that are doing this are really gaining.

“There are tremendous returns. They are investing the political capital and the capital capital to reprogram the public space for people traveling by bus, bikes or walking.”

Mr. White warmed further to the topic.

“Part of what fires me up, and what fires other people up, is: There is dysfunction now, but there is really opportunity by reorganizing cities. We can not only make cities more livable, but we can dramatically reduce our dependence on oil, we can go a long way to curb global warming, and—guess what?—we may improve democracy, and ourselves, in the process.”

It is hard to imagine exactly what a simple car owner from Queens would say to that.