The two candidates Mayor Bloomberg is vetting to head the city’s Department of Transportation stand poles apart on how to address the city’s transportation woes.

Transit experts are touting one of the candidates, Janette Sadik-Khan, 46, a senior vice president at the engineering firm Parsons Brinckerhoff, as the more progressive choice, saying she would focus on expanding mass transit options rather than making streets more accommodating of vehicles.

Her competitor, Michael Horodniceanu, 62, a former transportation department traffic chief under Mayor Dinkins with close professional ties to Commissioner Iris Weinshall’s administration, is widely viewed as the candidate who would stay with what critics have called the overly cautious and car-friendly course Ms. Weinshall has pursued over the past seven years.

In the next few weeks, Mr. Bloomberg will make his choice between what experts termed a “people-first” and a “car-first” traffic chief.

“If the mayor is creative enough to pick someone like Janette, it sends a message that he wants to have a legacy in taming city traffic,” the chief attorney of the Straphangers Campaign, Gene Russianoff, said.

“The right commissioner could do a lot more for pedestrians and bus riders and really turn the agency into a planning, not a traffic engineering, agency,” the executive director of Transportation Alternatives, Paul Steely White, said. “Transit-oriented development is Janette’s calling card.”

Ms. Sadik-Khan’s biggest asset, according to transit experts, is her ability to pull in big federal dollars to fund local transit projects. She oversaw a $4 billion capital budget when she worked for the Federal Department of Transportation.

Mr. Horodniceanu’s background, in contrast, is in traffic engineering. Transit experts say he would be more likely to focus on how to move traffic, not people, through the city. Mr. Horodniceanu earned a doctorate in traffic engineering, and currently runs the architecture and planning firm Urbitran.

Both candidates are expected to support the mayor on congestion pricing, a scheme under which drivers would be charged a fee to use the city’s most congested streets during peak hours. Mr. Bloomberg has said it is one option New York must consider to deal with traffic levels that are damaging to the city’s economy.

Ms. Sadik-Khan was considered for the commissioner post in 2000, when Ms. Weinshall was appointed by Mayor Giuliani — some say because of her political connections (she is married to Senator Schumer). Ms. Sadik-Khan was also one of Governor Spitzer’s top candidates to head the Metropolitan Transportation Authority, sources said, a position to which Elliot Sander was ultimately appointed.

With a new commissioner, “We hope for increased regional cooperation on transit and traffic projects, especially in securing federal funding for priority projects,” the president and CEO of the Partnership for New York City, Kathryn Wylde, said. She listed those priorities as increased ferry service, park and ride facilities connected to express buses, and bus rapid transit lanes.

As she prepares to leave local politics on April 13 to assume a position at the City University of New York, Ms. Weinshall responded yesterday to criticism that the transportation department under her leadership has dragged its feet in encouraging mass transit projects.

Ms. Weinshall told The New York Sun yesterday that her department studied 130 different communities in its quest to determine which neighborhoods would best be served by the faster bus lanes, known as bus rapid transit. “If the critics have a problem with that, I’m sorry,” she said. “But I’d rather be more comprehensive and inclusive than have the argument with people about why we didn’t look at their communities.”

Ms. Weinshall’s parting advice to her successor: “You’re serving all five boroughs. Each borough has distinct geography, concerns, and issues. There’s no cookie cutter approach.”

Ms. Sadik-Khan and Mr. Horodniceanu declined to comment for this article.