Atlanta's finest unveiled a battalion of Segway Human Transporter vehicles Tuesday. The battery-powered, two-wheeled scooters can top out at 15 mph.

Inventor Dean Kamen introduced the gyroscope-stablized scooters last fall after keeping them secret for months under the code names IT and Ginger.

Police in Atlanta — a traffic-snarled city that never met a motor vehicle it didn't like — are borrowing six of the scooters from Kamen's company for a two-month test run.

The department wants to know whether scooter patrols will be more effective than foot or bicycle patrols, and also hopes to use the machines to boost police visibility.

The scooter detects tiny shifts in body weight, rolling forward or backward depending on which way its user leans. Its gyroscopes make it difficult to fall from or to topple.

The police will use them in patrols at Hartsfield Atlanta International Airport and in the downtown business district. The debt-ridden department has not committed itself to buying any of the machines.

"Don't even ask me about the money," Maj. John Woodard said.

Atlanta is the first city to give the scooters a broad tryout, according to Segway officials. Georgia Power Co. and the city planning commission bought two each, and tourism officers who walk around downtown will share six.

Some critics have questioned whether Segways, which were designed for sidewalks, should mingle with pedestrians or be limited to bike paths and streets.

The Georgia Legislature passed laws limiting Segway speeds to 7 mph on sidewalks and 15 mph on roads, where riders will be required to wear a helmet. The vehicles can reach 15 mph in short bursts to help in pursuits.

How the scooters will hold up on the unforgiving streets of Atlanta, where tooth-jarring potholes sometimes go unfilled for months, remains to be seen. Police were put through an obstacle course as part of their Segway training.

"It just went right through everything," Officer Jennings Kilgore said. "It'll go about as fast as the normal person can run. It's a pretty good clip."

The police say they think the Segways would help them catch all but the fastest criminals. A special turbo key can send the Segway zooming off at 15 mph — the normal top speed is 12 — while the fastest humans can top 20 mph, though only for a short distance.

If anything, Woodard said, the Segway scooters are more agile and stable than bikes, if considerably slower in hot pursuit.

"I don't think anything is perfect in those situations," he said. "We won't know till we get involved in some real pursuits."