When high-tech bicycle rental scheme Mobike dropped hundreds of its distinctive orange and silver bikes across the northern British city of Manchester, it promised a cheap, flexible and low-carbon way to travel.
In September, the firm announced it was pulling out of the city, citing significant bike losses due to theft and vandalism and following complaints of anti-social use and street clutter.
It was just the latest growing pains of dockless bike and scooter schemes which have exploded across many world cities.
While fans say they help free city centers from traffic and promote cycling, critics argue they have taken advantage of a lack of regulations and are riding roughshod over local communities. In many places, the bikes and scooters have been targets of vandalism, treated a scourge of the urban landscape. . . .
Critics have complained about the number of dockless vehicles left vandalized or dumped in public, while disability campaigners say they create obstructions after being left strewn across paths for hours or even days.
"We are hearing about problems every week," said Francesca Di Giorgio, policy manager for Britain's Royal National Institute of the Blind. "You can never plan for where a dockless bike is going to be - the very temporary nature means you never know where one is going to be laid across a path."
CoMoUK said its accreditation scheme sets response times for dealing with obstructions.
Mobike also employs a team that deals with vandalized or inappropriately parked bikes, said Milton, though he acknowledged in some cases it might take several days for a call to be acted on.
Claims that the bikes create street clutter are a more complicated question, he said.
"When is a bike that is parked a dumped bike? It's almost a mental transition," he said. "People don't see a car parked and say, 'That car has been dumped'."
The sight of brightly colored dockless bikes and scooters in urban areas has highlighted a lack of bicycle infrastructure in many cities.
One of the longer-term effects may be to put pressure on local authorities to create facilities like bike parking, predicted Geoffrey Dudley from the University of Oxford's Transport Studies Unit.
He said cities may ultimately find it is worth paying for infrastructure to support dockless users - but it will probably come at a price for the companies in the form of new regulation.
"There's got to be some sort of rules in the end," he said.
