Two teens rented electric scooters and drove them along a busy two-lane road, police said.
The equipment is tested in the Tees Valley area and can only be used on bike paths and roads with a speed limit of up to 40 mph.
Cleveland Police said they arrested two teenagers who rented the scooters and drove them along the A19 to Teesside Park on Thursday.
Police did not say how old they were or if they had a driver’s license.
Ginger, the company running the trial, was asked how the system would prevent those who aren’t licensed to use it from renting the vehicles, but did not comment.
A force spokeswoman said none of the boys was wearing protective equipment, such as helmets or high-visibility clothing, as recommended by government guidelines.
Temporary Superintendent Graham Milne said, “Hiring electric scooters might sound a little fun to some, but they’re not toys. “
According to the guidelines, 11.5mph e-scooters can be driven on any road outside of the highway.
But a Cleveland Police spokeswoman said they were not allowed on roads with a speed limit above 40 mph.
To be able to rent an e-scooter, a driver must have a provisional or full driving license.
Tees Valley mayor Ben Houchen, who defended the pilot, said the riders’ actions were “illegal” and “a gross violation of the rules”, describing the pair as “idiots”.
He said more than 500 trips had taken place since the start of the trial on Monday, “an overwhelming majority of which went without incident.”
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