It was supposed to launch a revolution in personal transport but has been stopped in its tracks by a strict interpretation of a 170-year-old law.
The British government has declared that the Segway Human Transporter — a $5,000 self-balancing scooter — cannot be used in any public place.
The scooter, which has been described unkindly as a pogo stick on wheels, arrived with great fanfare in 2001.
Dean Kamen, its American inventor, suggested that it would be the solution to all transport woes. Queues of exhaust-belching cars would soon be replaced by squadrons of Segway riders gliding silently along at 12 mph.
Kamen said then that it "will be to the car what the car was to the horse and buggy."
The hyperbole provoked a backlash in the media, which largely ridiculed the invention and ignored the technical genius of the gyroscopes and microprocessors that kept it upright.
However, after a slow start, sales have picked up in dozens of countries.
France, Spain and most U.S. states permit it on sidewalks; Austria and the Netherlands allow it on cycle paths, and in Italy it can trundle on both. On sidewalks, the limit in Italy and France is 6 kmh (3.7 mph).
In Britain, the Department for Transport has welcomed the scooter with a double whammy, invoking the Highway Act of 1835 to ban it from sidewalks and EU vehicle-certification rules to keep it off roads.
In a document, "Regulations for Self-Balancing Scooters," the department says: "You can only ride an unregistered self-balancing scooter on land which is private property and with the landowner's permission."
It rejects proposals that the Segway should be treated like the faster electric bicycle.
It says: "A self-balancing scooter does not meet requirements [for electric bicycles] as it cannot be pedaled."
The document also advises Segway users to wear "appropriate safety clothing at all times."
Bae Systems, which developed the Segway gyroscopes at its Plymouth, England, research center, accused the department of failing to test it properly.
Andy Hughes, a spokesman, said that four officials attended a testing session, three of whom refused to ride it. The fourth traveled only 100 yards.
"The department seems reluctant to accept new technology, and there is a degree of [butt]-covering in the regulations," Hughes said.
Those regulations have also angered a small but determined group of Segway commuters, who insist that they will continue to ride to work, saying they pose less risk to pedestrians than a clumsy jogger.
Isidore Margaronis, 56, the director of a shipping company, has commuted by Segway for the past three years from Notting Hill in west London to his Piccadilly office.
He said: "The department is taking a bureaucratic and pernickety attitude. If we have to wear protective clothing to do 12 mph, then joggers should have to wear motorcycle leathers."
His journey takes 20 minutes by Segway or 40 minutes by bus or Tube.
"I prefer the Segway because, unlike with a bike, you don't arrive in a lather," Margaronis said. "I can wear a suit and go straight into a meeting, taking my Segway up in the lift."
Jeremy Greaves, an executive for EADS, the aerospace company, said: "How can Tony Blair trumpet Britain's environmental commitments when the Government tries to stop people using such a clean and sustainable mode of transport? I'm going to carry on using it."
Greaves, 38, added that the only requirement for riding a Segway was to be thick-skinned.
"Some people sneer, but they are probably jealous that I am getting to my destination faster and having fun."
A study by Kaiserslautern University in Germany found that it took a few minutes to grasp the basic skills of Segway riding, and three hours to become proficient.
A rider simply leans forward to move forward and back to stop. On the original model, steering is controlled by twisting a handlebar grip. On a newer version, riders push the column left or right.
The German study found that learners had a slight tendency to topple backwards if they stopped too quickly.
A department spokesman hinted that the regulations might be reviewed, adding: "We are still in contact with the company and keeping up to date with developments."