A new study shows people hurt riding an e-scooter sustain injuries like those from a car crash or falling from a substantial height, and need costly surgery.
A paper in the New Zealand Medical Journal catalogues a period from October last year until February at Auckland City Hospital.
It said 21 people presented with injuries from falling off e-scooters and needed surgery costing $360,557 - with the total cost to the economy including lost wages of $404,925.
These figures do not include the cost incurred by other injured people needing treatment at the hospital's emergency department, or from GPs or private health care. The report said these combined were likely to be more than spent on surgeries.
The report said e-scooter injuries were particularly challenging - causing the types of injuries associated with car crashes, or a fall from a substantial height.
This made surgery needed to treat them more difficult and costly, and forced other people needing emergency operations to wait longer.
Nineteen of the 21 people in the report needing surgery were riding Lime scooters, but Lauren Mentjox from the company said the accidents needed to be put into context.
"During the period in the study we had nearly 200,000 riders and we'd done just under a million rides," she said.
"Any injury is one too many, but in the overall scheme of things it's a very small percentage of rides."
She said crash numbers during the period scrutinised in the study were not typical because it coincided with a software glitch that caused their scooters' wheels to lock up randomly - causing injuries in New Zealand and world-wide.
ACC has spent $1.7 million since October on Aucklanders hurt while riding e-scooters.
Ms Mentjox said all forms of transportation had risks, and the scooters brought huge benefits to New Zealand.
"We increase traffic to retail stores and cafes, we improve productivity, for example, by reducing congestion.
"In Auckland ....59 percent of Lime trips ... are done during peak commuting hours.
"And on top of that we've got some stats on how many car trips we've avoided, and that's currently standing at about 500,000 in Auckland."
Auckland Council said in a statement it had been working with e-scooter operators on more stringent safety initiatives, including lowering speeds in some areas.
It said riders needed to be responsible and take care.
The e-scooter trial in the city was rolled over in May and runs until the end of October.