Postie Spencer Salt was one of the first to drive the new mail delivery vehicle unveiled by New Zealand Post in New Plymouth, in June.
New Zealand Post's new delivery buggies are having a hard time keeping their wheels on the ground.
The New Plymouth trial of the three-wheeled, hi-tech vehicles has recorded five incidents since the programme was rolled out, in June.
In the most recent incident, a postie sustained two fractured ribs after he lost control of the vehicle when rounding a corner.
The New NZ post buggies have been a huge success and very popular with the public. Posties show us the future of delivering our mail and the benefits it has.
NZ Post delivery man Spencer Salt was taken to the Westown Medical Centre, New Plymouth on Tuesday, July 21, NZ Post's Taranaki Delivery Leader Shona Gold said.
NZ Post was carrying out an investigation into the incident, but Gold said the driver, Salt, was "going fast on the road when approaching a corner".
The vehicles can reach speeds of 45km/h.
Salt's injuries were assessed, revealing he had fractured two ribs, however he was cleared to resume light duties at work that week.
When Salt was approached by Stuff, he said he felt uncomfortable providing further comment on Tuesday's event.
No major injuries had resulted from the other four incidents, Gold said.
"They all happened at low speed, three of them when the vehicles were entering or reversing out of driveways, and one when the vehicle hit an obstacle.
"In each case, the delivery agent simply stepped out of the side of the vehicle and was unharmed."
Gold said NZ Post would continue to work with the Kyburz vehicle manufacturer to better understand how to safely operate the vehicles.
"All types of vehicles used by Post have some element of risk - including vans, motorcycles and bicycles - and we take those risks into account in our safety training programmes.
"These vehicles are an important part of our future but there is no way we will compromise the health and safety of our people. We are doing everything we can to ensure they are operated safely," she said.
New Plymouth delivery agents received two days of operation and safety training before being cleared to use the vehicles.
New Plymouth was the pilot site for the new motorised vehicles, and NZ Post would begin reviewing the pilot results in August to determine what changes to make before continuing the roll out nationally.
"These vehicles are an important part of our future but there is no way we will compromise the health and safety of our people. We are doing everything we can to ensure they are operated safely," Gold said.
A Worksafe spokeswoman confirmed they were notified of the incident on July 21, but the extent of the injuries were not severe enough to warrant an investigation.