New roundabouts on Waikato highways meant to "calm" drivers are instead infuriating them and some say their design could result in fatal accidents.
But the Transport Agency says the roundabouts should improve safety and reduce fatalities and drivers just need to slow down when entering them.
Several motorists have complained to the Herald about the new SH1 roundabouts north of Hamilton, one of which was the scene of a truck rolling at Taupiri at the intersection of SH1 and SH1B last week.
They say the roundabout's camber is too high on the inside and too low on the outside, making driving around it difficult.
"They are accidents waiting to happen," said Susan Irs in an email.
"We have a Ford Escape and with just the extra height find that using the roundabouts is quite nerve-racking, so for trucks, campervans they must be diabolical. Perhaps [the agency] would like to go and take a look at them and get them redone before someone is killed," she said.
Ken Shirley, chief executive of the Road Transport Forum, said the newly designed roundabouts could have been overdone to the point where they became "dangerous and very awkward".
"We have an ongoing tension in terms of those sorts of conflicting objectives of deliberately calming traffic but then posing an unnecessary obstacle on what should be a smooth, transitional roundabout."
But Transport Agency state highway manager Kaye Clark said the intersections were upgraded to improve safety and cut traffic delays due to advance work for the Ngaruawahia section of the Waikato Expressway that is due to open next year.
The raised centres of the Taupiri roundabouts were to increase their visibility to motorists and to reduce the incidence and severity of fatal or serious-injury crashes.
"As with any intersection, motorists need to ensure that they drive to the conditions as they negotiate ... them."
The cambers were designed to fall away to allow rainwater to drain and also encourage drivers to be more cautious about the speed at which they entered.
The crash at Taupiri was the first since recent work was completed on the roundabout. Before this there were 18 crashes at the intersection. There have been four non-injury crashes at the Horotiu roundabouts since they opened in December.