in Pennsylvania, Santa Clara in California, and others in Maryland -- also employ the Segway.

It's also found its use in airports like Baltimore-Washington International, and Chicago's O'Hare International Airport, where what started three years ago as an experiment ended with a large contract with the city. This spring, Chicago announced a new $580,000 contract with Segway that will add as many as 100 new machines to the 50 already in use in the city. It's the largest municipal contract since Segway launched in 2001.

Other Segway customers include Seattle, which uses the vehicles to go door to door and read residential gas meters, and to retrieve coins from parking meters.

Inexplicable Shutdown

The Segway is powered by noncombustible lithium ion batteries and controlled by computer software. "It's a marriage between a computer and a transportation device," said Klee Kleber, vice president of marketing at Segway Inc.

The "brains" of the Segway include five gyroscopic tilt sensors and two accelerometers that work like an inner ear to feel things such as the driver leaning, the slope of a hill and the machine's speed. As the driver's center of gravity shifts, the gyroscopes process this information about 100 times a second and convert it to wheel motion.

The newer machines launched in August 2006 come with LeanSteer handlebars -- a new structure that moves to the left or right as the machine turns.

In addition, the Segway has an alarm that lets law enforcement officers or paramedics park the machine to tend to business, without worrying about someone taking it for a joy ride.

The Segway's InfoKey controller -- a device that looks like a digital watch -- lets the driver control the vehicle, turn it on and off, and activate the alarm.

When the Segway alarm is triggered, the wheels lock and an audible alarm is sounded; the vehicle also vibrates, making it uncomfortable to ride if tampered with.

A safety mechanism shuts down the machine if something goes wrong. Armijo and Linse have both experienced the inexplicable shut down of a Segway while on patrol. "It did a little shrug, and the red light came on, and it shut down," Armijo remembered. "I couldn't restart it."

In both cases, the Segway had to be sent to the manufacturer for repair. Armijo was disappointed that it took six weeks to get it back. Software problems prompted a recent recall of all Segways after six of the machines malfunctioned and caused minor injuries to the operators. Kleber said software upgrades to all machines took care of the problem.

Armijo was just glad to get his back.

"It's a really good tool," he said. "Fortunately we have three of them but one is a backup, and the captain likes to come and ride with us so we need all three of them."

One advantage of the Segway is it can go anywhere. "We're much more mobile with the Segways," Linse said. "Because the Segway has nonmarking tires and produces no emissions, they're able to actually enter the downtown buildings, ride on the elevator and go right up to the patient's side."

The ALS team works every day, even during the winter when they patrol Chicago's Pedway System -- an underground walkway that covers about a 40-block area. They can easily pop up from the Pedway System to tend to anyone needing assistance in the downtown area.

The fire department customized the ALS Segways to include a defibrillator, diagnostic equipment, intravenous solutions, obstetrical kits and pharmaceuticals. Segway also puts out a police package that includes a handlebar bag for gear, accessory bar for lights and siren, an LED taillight and cargo frames. The regular model is about $4,500 and the police package retails for $5,495.

Linse said he and the ALS teams have used the Segway for about a year now, and they are sold. "I'd get more if I could."

Jim McKay, Justice and Public Safety Editor  |  Justice and Public Safety Editor