Mayor Vincent C. Gray joined two D.C. Council members in unveiling an ambitious bill to overhaul the city’s taxicabs Monday, calling it a big step toward a “world-class transportation system” for the city.

But a small group of protesters crashed his news conference Monday, denouncing the legislation as unfair to cab drivers and heralding testy battles to come.

At a news conferencethe John A. Wilson Building news conference, Gray (D) and council members Mary M. Cheh (D-Ward 3) and Tommy Wells (D-Ward 6) said the bill would make the taxi industry more responsive to residents. It would, among other things, mandate credit-card payment options, satellite navigation systems, new training for drivers and a single paint color for the city’s 5,000-plus cabs.

“What we have now is a total top-to-bottom transformation,” Gray said.

Under the legislation, to be introduced at Tuesday’s council meeting, the D.C. Taxicab Commission could establish a surcharge, perhaps 50 cents per trip, to help drivers pay for improvements to their vehicles through grants or low-interest loans.

Cheh, chairman of the transportation committee, said the public, including drivers, would have multiple opportunities to weigh in on the legislation. But as she described the details of the bill, one driver interrupted her, shouting, “I haven’t heard anything that is going to benefit me.”

The man, who complained the measure would make cab-driving a “minimum-wage job,” was later escorted out of the mayor’s briefing room. A few minutes later, another driver verbally sparred with Gray after the mayor said he had previously met with drivers to discuss some of their concerns. “No, you didn’t, Vincent,” said Larry Frankel, an advocate for some D.C. taxi drivers.

“Don’t tell me what I did,” Gray responded.

After the briefing, Frankel told reporters that the legislation would cost drivers too much. “I don’t know of a single company that wants to put these instruments in [cabs] for free,” he said. “You are talking about close to $3,500 per cab.”

Drivers also questioned a provision in the bill that would allow the Taxicab Commission to set quotas on the numbers of drivers and cabs.

The proposals are “really an extension of the medallion bill,” said Carolyn A. Robinson, a Yellow Cab driver, referring to the failed attempt last year to limit the number of taxis on District streets. “They are trying to make this like New York, but D.C. is a diverse metropolitan city like no other.”

But Ron Linton, chairman of the Taxicab Commission, said there are no plans to establish overall caps on the number of cabs in the District, despite language in a draft bill stating it is “authorized to establish a public vehicle-for-hire licensing quota.”

Linton said the language was included to limit the number of people applying annually for licenses but not the overall number of cabs.

Among the bill’s other provisions:

● It would digitize what is now a paper recordkeeping process, mandating devices that send trip data to the commission in real time and “can record and report all fares and earnings for tax purposes.”

●Cabs would be equipped with roof lights that “clearly identify when a taxicab is occupied, on-call, off-duty, or available to accept a fare.”

●A new driver training course envisioned by the law would cover the “geography of the District, with particular emphasis on major streets and avenues”; “[p]ublic relations skills, including cultural awareness and sensitivity training”; and “[d]riving skills and knowledge of the rules of the road.” Would-be drivers would have to pass an exam of no fewer than 100 questions.