New Zealand Post's electric "Paxster" vehicles have been involved in 34 crashes since the multi-million investments hit the streets - causing damage to public property and injuring postal workers.
Capable of speeds of up to 45km/h, the golf cart-style delivery vehicles began a nationwide roll-out last year, with state-owned business NZ Post announcing $15 million had been set aside to invest in the units over two years.
According to data released by NZ Post under the Official Information Act, Paxsters were involved in 30 crashes during last year's national launch, with a further three in 2015 and one more in 2014.
Two of the incidents involved collisions with moving vehicles and were attended by police.
NZ Post said no members of the public had been harmed in any of the crashes. However, public property has been damaged - though the state-owned enterprise refused to reveal to what cost.
"...Items such as letterboxes, concrete posts and vehicles were damaged. We do not discuss details of insurance matters," an NZ Post spokeswoman said.
The incidents have also seen postal workers suffer injuries. NZ Post said no injuries had caused staff to take time off work, but didn't confirm how many staff have been affected or the exact nature of each injury.
"...There were no injuries in 2016 as a result of a Paxster "crash" that required time off work for a delivery agent," the spokeswoman said. "While we wouldn't discuss an individual's injuries, the nature of non-time off injuries can typically include minor bruises and cuts."
Southern president of the Postal Workers Union, John Maynard, said "we understand there have been two crashes with injuries to the drivers."
Maynard said while no members of the public had been hurt, the union still has worries over public safety, particularly where children and reversing Paxsters are concerned.
"Many of the crashes have been incidents like backing into objects or brushing against poles," Maynard said.
"They have a significant blind spot. I have stepped back four metres before a Paxster driver could "see my elbow". A child could be anywhere from immediately behind to more than four metres behind and they would not be seen by the Paxster driver."
Maynard said the union was pushing for reversing cameras to be installed.
Paxsters have an exemption from the New Zealand Transport Agency - section 2.13(1) of the Land Transport (Road User) Rule 2004 - allowing the vehicles to be driven on footpaths.
NZ Post said staff training and safety was of utmost importance.
"We are always extremely conscious of public and staff safety and work very hard to keep incidents to a minimum. This applies equally to Paxsters as it does to bicycles and all the other modes of transport we use," the spokeswoman said.
"We are always looking to improve our training and standard operating procedure. This applies to all of our modes of transport."
The data released by NZ Post also shows a reduction in crashes attributed to bicycles since the national Paxster roll-out, with 309 crashes in 2015 dropping to 254 last year.