A mobility scooter was caught on camera being driven along a busy inner-city ring road.
Motorist Linda Miller captured the dashcam footage on the A601 in Derby on her way home from a shopping trip.
She complained to police after witnessing the "dangerous" episode.
While some motorised scooters can legally be driven on roads, a Derbyshire Police spokesman said it was "not really appropriate" for the vehicle to be on the ring road.
Mrs Miller, from Littleover, said she saw the scooter "tootling along" on Tuesday.
The ring road has a 40mph speed limit, although the scooter appeared to be travelling far slower than that.
Mrs Miller, a retired phlebotomist, said : "We were just driving along coming around Derby where the A6 goes off, on the north side of Derby.
"I looked sideways and there was this mobility scooter tootling along in the far left-hand lane.
"It didn't have a licence plate.
"It just looked so dangerous. It's a bit of road where you've got a lot of cars coming on, and going off, across five lanes.
"It's bad enough when you're in a car - it's a horrendous bit of road."
The Highway Code states scooters with an 8mph (12.9 kph) speed limit can be used on dual carriageways - with a speed limit of under 50 mph (80kmh) - but only if they have a flashing amber beacon.
"People need to ask themselves if it is a sensible thing to do," Mrs Miller said.
"I did report it to 101 in the end - and I have a case number but I don't think it will go any further."