On the Move.

Driverless Taxi

Want to visit a friend on the far side of town? Imagine walking down the block to a PRT (Personal Rapid Transit) station. You buy a ticket, and a central computer miles away dispatches a driverless subway to pick you up and whisk you nonstop to your destination. No way? Researchers at Raytheon, an engineering company in Lexington, Mass., are perfecting the PRT2000--an automated public transport system--at their test site. There, three rubber-tired vehicles glide along a 610-m (2,000 ft) circuit of elevated rail tracks at 130 km (80 mi) per hour.

Raytheon's scheme for the next century: vehicles similar to "Peoplemovers" (already in use in downtown Miami and Detroit) that speed on 6-foot wide railways 16 feet above city streets. Passengers will head to hundreds of PRT stations one-third of a mile apart. But unlike Peoplemovers, central computers calculate the most direct route specified on each passenger ticket, then guide you to the car going your way. Engineers plan construct a working prototype of PRT2000 in Rosemont, Ill., within three years. Get ready to glide!

Mini Wheels

It's small enough to weave between lanes and park in a motorcycle space. Smart Cabrio may be your best bet for beating next century's traffic gridlock. Smart, a division of Daimler-Chrysler, launched the 2.5-m (8 ft) long, 1.5-m (5 ft) wide, and 1.5-m high Cabrio in 1998.The Cabrio convertible version debuts in March 2000. Made in Germany and now sold in Europe, the two-seater Cabrio gets 21 km per liter (50 mi per gallon), making gas station visits--like the Cabrio itself--well, minimal.

PERSONAL FLY MACHINE

You step into a machine and secure yourself in a standing position. Then, using regular gas, you crank up the engine--and blast off! In the next decade you may hit the skyways instead of the highways in your own air scooter.

With funding from NASA, flight engineer Michael Moshier is testing a prototype, or preliminary model, of his personal flying vehicle. SoloTrek stands 2.4 meters (8 feet) high and 2.7 m (9 ft) wide. It takes off like a helicopter, climbs to 3 kilometers (10,000 ft), and breezes along at 128 km (80 mi) per hour. SoloTrek gets 32 km (20 mi) to the gallon and can fly for 90 minutes, or about 193 km (120 mi), before needing a refuel. "We've dreamed of such a vehicle for many years," says Moshier. "Now the dream is becoming a reality."

How does it work? You stand on footrests and use your hands to grip levers that control two circular air ducts, or fans, above your head. When you ignite the engine, the spinning fans generate enough thrust, or force of downward air, to render the craft airborne. (The principle behind takeoff: Newton's Third Law of Motion--for each action there's an equal and opposite reaction.)

You use hand levers to steer the vehicle through the air. To go forward, you tilt the fans backward. Rushing air pushes downward an(l backward, propelling the machine forward and maintaining what Moshier calls hover, or float. In the same way, by tilting SoloTrek's fans right or left, you navigate your turns. To land, you slow the speeding fans to reduce the downward air thrust, allowing gravity (Earth's downward pull) to gently pull SoloTrek to the ground. The vehicle weighs 245 kilograms (540 pounds), and can land on "any level surface larger than a dining room table," says Moshier.

You'll have to pass a flying test to step into SoloTrek. To start the craft's engine, you must first be recognized by a retinal scanner (a machine that identifies you by your retina, or inner eye). Ready for takeoff?

DO YOU KNOW?

Wheeled vehicles were invented:

* around 3000 B.C. in the Middle East

* in the Renaissance

* around 1900 by Henry Ford.

This Issue's Answers

p. 18: around 3000 B.C. in the Middle East