Outside Colombia, Bogotá is better known for its association with cocaine trafficking than for its traffic congestion.

For many of the city’s 7 million residents, however, it was the bumper-to-bumper traffic that topped their list of grievances as of 1998, when Enrique Peñalosa was elected mayor. During his three-year tenure, Mr. Peñalosa devised and implemented a comprehensive city bus system that has eased congestion in Colombia’s capital and cut Bogotános’ commutes to work by hundreds of hours a year.

In his keynote address today at a New York transportation conference, Mr. Peñalosa will discuss the overhaul of Bogotá’s mass transit system, and ways traffic could be eased along New York’s car-clogged streets. More than 500 people, including elected officials, mass transit advocates, community activists — and even celebrities such as actor Matthew Modine and the musician Moby — are expected at the day-long conference, hosted by Manhattan’s president, Scott Stringer.

In a phone interview from Bogotá on Tuesday, Mr. Peñalosa said enacting stricter parking restrictions, erecting barriers to protect bicycle lanes, closing Broadway to automobile traffic on Sundays, and creating lanes restricted to bus traffic could go a long way toward improving the traffic flow and the quality of life in Manhattan. “In New York, sometimes the buses are so slow that it’s faster to walk,” Mr. Peñalosa, who maintains an apartment in Greenwich Village, said.

“We cannot talk about transportation until we know what kind of city we want to have,” he said. “The type of transportation generates a certain type of city.”

As mayor, the 1977 Duke University graduate and son of a former United Nations ambassador oversaw the creation of the $800 million TransMilenio bus system that travels in cordoned-off lanes along major city arteries. TransMilenio, which covers some 300 miles of road, has to a large extent supplanted what locals describe as a confusing and slow-moving free-for-all in which dozens of private bus companies traveled various city routes.

“You had to memorize the names and numbers of the routes,” a 28-year-old Bogotá resident, Mateo Saenz, said of the pre-TransMilenio system. “It was really difficult because buses would just stop in the middle of the road to pick up a passenger. If you were in a car, you’d have to shout or honk, and, still, you wouldn’t move.”

These days, Mr. Saenz said his prerush hour commute takes about half an hour. “Before, you’d never know,” he said. “It could take an hour or two hours — or 15 minutes if the driver decided to bypass all the red lights. It was completely unregulated.”

During Mr. Peñalosa tenure, the city also put up stone barriers to keep vehicles from veering into bike lanes; widened sidewalks, and conducted an experiment in auto-free urban living — closing city streets to private vehicles for one 13-hour period in February 2000. The former mayor led a parade of cyclists on that car-free Thursday, which is now an annual event in the city.

Acknowledging the vast differences between New York and Bogotá, the latter of which is far poorer and has no subway system, Mr. Peñalosa said not all of the recent transportation reforms instituted in his hometown would be applicable here.

Bogotá mayors cannot serve two terms consecutively, and Mr. Peñalosa, a trained economist who left office in 2001 and is said to have presidential ambitions, told The New York Sun he plans to run as an independent in the city’s mayoral election next year. If elected, he vowed that transportation and quality of life issues such as the overcrowding and boarding waits on TransMilenio buses would remain on the front burner. “In cities, there’s always a conflict between being friendly to cars and being friendly to people,” Mr. Peñalosa said. “The question is: How do you harmonize those issues?”

The Colombian politician, who heads up a Bogotá-based nongovernmental organization and has served as a visiting scholar at New York University’s Wagner Rudin Center for Transportation Policy & Management, said he would speak today “not as an adviser to New York, just as someone who has some interesting experiences to share.”

Today’s conference is the first step toward addressing long-term solutions to New York’s own “transportation crisis,” Manhattan’s deputy president, Rose Pierre-Louis, said. “In order to continue to grow the economy — this is the economic engine, not just for New York City, but also for New York State —we need to look at what changes need to be made over the next 25 to 50 years,” she said. Ms. Pierre-Louis said Borough Hall was interested in looking at the effects of New York’s projected population growth on traffic and mass transit.

Mr. Stringer, in addition to the city’s Department of Transportation Commissioner, Iris Weinshall, and various transportation consultants and advocates, will address the gathering, which begins at 8:45 a.m. at Columbia University’s Alfred Lerner Hall and is free and open to the public.

“Transportation is a very peculiar problem,” Mr. Peñalosa said. “Unlike education or housing, transportation tends to get worse as we get richer. It’s not a problem that can be solved with money — only with changes to our way of life.”