What would New York City be without yellow cabs? New Yorkers and visitors could soon find out.

New York taxi drivers this week announced plans to strike in September in opposition to global positioning devices. The city's Taxi and Limousine Commission (TLC) announced several years ago that it would switch to hybrid vehicles and wireless devices with GPS or similar tracking technology. The New York Taxi Workers Alliance has protested the plan in the past and now is talking about a full-fledged strike.

Drivers complain that they don't want to be tracked and can't afford the installation expense, which is estimated to range from $3,000 to $5,000 per vehicle. They claim the devices could be used to monitor speeding, whereabouts, and other activities in violation their privacy rights.

New Automatic Vehicle Locator technology will log trips automatically, which the TLC said would improve accuracy and help passengers retrieve items they leave behind in cabs. It will not provide passengers with directions, which could cause an annoyance by encouraging "back-seat drivers," according to the commission. The TLC also has said the technology won't be used to track drivers.

A Driver Information Monitor will allow drivers to receive messages when the car is stopped. The messages will contain information about lost property and traffic congestion. Text messaging also will be used to communicate in the event of a citywide emergency and will notify drivers when large public events are scheduled. Some messages will contain a pre-programmed response allowing drivers to respond to queries about lost property claims with the touch of a button.

When the commission announced plans for mapping and automated data collection about three years ago, chairman Matthew Daus said the improvements would enhance the fleet's technological capabilities, improve passenger convenience, and bring "the already high quality of taxicab service to the next level."

Some hybrid, high-tech cabs already are on the streets. Passengers in some cabs can watch video information segments and control volume and other features on small screens mounted on the back of the front seat.