The District's new taxicab commission, charged with reforming the city's much-criticized taxi industry, voted yesterday at its first meeting to substantially increase fines in an effort to improve service and reduce the number of illegal cabs operating in the city.

The new penalties, which include a fine increase from $50 to $500 for unlicensed drivers, are scheduled to be enforced beginning July 3.

The commission also approved plans to increase as soon as possible the number of license inspectors from four to eight, and officials said that Police Chief Maurice T. Turner Jr. had promised to step up enforcement of taxi regulations by police officers. Commission spokesman David A. Watson said an additional 11 license inspectors are expected to be be hired later.

Although the new fines have not yet taken effect, police officers in recent days have set up taxi checkpoints at various locations, including the Key Bridge and the William H. Taft Memorial Bridge on Connecticut Avenue, where they have pulled over cabs to check whether they are properly licensed.

"We have some hardworking taxicab drivers, but on the other hand we have some who blemished the industry," said Mayor Marion Barry, who appeared at the meeting held at the Anacostia Business and Professional Building, 2041 Martin Luther King Jr. Avenue SE. The commission "is moving in the right direction {by} increasing fines."

One of the new commission's tasks will be to "make sure taxi drivers are communicating in the language that {most} people speak -- that tends to be English," the mayor said.

The District's cab industry -- which comprises 10,000 licensed cabs and 12,500 drivers, of whom about 3,000 are considered illegal -- has been widely criticized in recent years for the poor condition of some vehicles and the failure of some drivers to know the city or be able to converse with passengers. The city government has been faulted for lax enforcement of cab regulations.

Earlier this year, Sen. Tom Harkin (D-Iowa), chairman of the Senate Appropriations subcommittee on the District, drew attention to problems in the industry and said he intended to make changes one of his priorities.

Commission Chairman Arrington Dixon, a former chairman of the D.C. Council, said yesterday that the increased fines and stepped-up enforcement are part of an effort to have a "model" taxicab industry.

Dixon said the panel also will work to improve a mandatory hackers course that is taught at the University of the District of Columbia. In addition, the commission will begin a longer-term study of whether the city should continue its unique zone-based fare system or switch to taxi meters, an issue that is likely to spark controversy.

Also appearing at yesterday's commission meeting was a group of taxi drivers who have formed a union. "For far too long, D.C. cabdrivers' voices have gone unheard," said Joanne Bell, president of the new D.C. Taxi Drivers Association, which is affiliated with the Communications Workers of America.

The taxi commission replaces the Hacker's Appeal Board and also is chartered to hear disputes between passengers and drivers. The 13-member commission was appointed earlier this year by Barry after a fight with the D.C. Council over who would be named to the panel.Staff member Kenneth Greenberger contributed to this report.