A group of New York City taxi drivers is threatening to go on strike Wednesday over new rules requiring all cabs to have GPS and touch-screen monitors that will let passengers pay by credit card.

While playing down the likelihood of widespread disruption, Mayor Michael Bloomberg announced plans Tuesday to institute group rides citywide, including from LaGuardia and Kennedy airports, if cabbies strike. Currently, drivers are allowed to pick up only one fare at a time.

"Our expectation at the moment is that there will be very few, if any, taxi drivers striking tomorrow and the next day," Bloomberg said at a news conference. "I think cooler heads will prevail."

The New York Taxi Workers Alliance is calling for drivers to go on strike for 48 hours beginning at 5 a.m. Wednesday to protest a requirement that the city's more than 13,000 cabs have the high-tech equipment when they come up for inspection, starting Oct. 1. The alliance claims to represent about one-fifth of the Taxi & Limousine Commission's 44,000 licensed drivers.

Some cabbies fear the video systems could be used to track drivers' movements and that drivers would get stuck paying hefty fees for credit card processing.

"They are putting in all this stuff, and it's all bad," said Singh Kuldip of Jersey City, N.J., a native of India. "Well, the credit card stuff is good. But this GPS thing is bad. They will be tracking us all over."

Several other drivers' groups that represent thousands of city cab drivers have released statements opposing the strike.

Bloomberg said the group rides to the airports -- as well as other contingency plans encouraging people to use mass transit -- would go into effect after midnight Tuesday but would be canceled if the taxi commission determines that the labor action isn't having much impact.

Under the plan, cab drivers would be encouraged to pick up more than one passenger going to and from Kennedy and LaGuardia from Manhattan. Passengers agreeing to that option would be charged a $30 flat fare per person from Kennedy and a $20 per person fare from LaGuardia; if they declined the group ride option, normal, metered rates would apply.

For group rides within the city, each passenger would pay on a zone system -- $10 for the first zone and $5 for every additional zone they cross. Manhattan is divided into four zones.

In addition, the Metropolitan Transportation Authority, which runs the city's subways and buses, plans to provide additional service on routes to and from LaGuardia.

The New York Police Department will assign extra police officers to taxi garages and transportation hubs like Grand Central Terminal and Pennsylvania Station, and plainclothes officers will ride in some taxis.

"We are taking these steps to ensure the public safety and to guard against reprisals against cabbies who elect to drive during the planned strike," said NYPD Commissioner Raymond Kelly.

Alliance spokeswoman Bhairavi Desai said she expected "an overwhelming majority of the entire work force, not just the alliance" to walk out.

She said there had been discussions with the mayor's office but they did not resolve the issues.

The group, which is an advocacy organization, not a labor union, organized a one-day strike in 1998 that caused headaches for many residents and tourists and had city officials hustling to line up buses and vans.

Bloomberg noted that drivers had gotten two fare increases in recent years in exchange for putting the new technology in their taxis.

One driver outside Pennsylvania Station said he would work despite the strike.

"No. I can't afford two days off," said Mohammad Osman. "You have to understand, it's very hard for me."

The cabbies picked a busy week for a possible job action, with the city hosting the U.S. Open tennis tournament and New York Fashion Week and hordes of New Yorkers returning from summer vacations after Labor Day.

Some New Yorkers seemed sympathetic to the drivers' concerns.

"I can understand why they have an issue with GPS," said Chris Bungarz of Long Island as he got out of a cab at Penn Station. "But it seems their contract gave them a fare hike in exchange for it. They can't have it both ways."