A motorcyclist group says aggressive drivers are endangering riders on the Rimutaka Hill and have even tried to run them off the road.
The Wellington branch of the Bikers Rights Organisation, or 'BRONZ', says while a small group of bikers do ride dangerously, the vast majority are responsible and the Automobile Association is backing their call for motorists to drive more carefully around them.
The president of the Wellington branch, Byron Cummins, said whatever the vehicle, there will always be those who try to break the speed limit for fun or will take risks, and motorcyclists are no exception - although the number is small.
But he said cars and trucks frequently cut corners and cross the median line, while young men use it to practise 'drifting' and intentionally try to push riders off the road.
"There are enough aggressive car drivers on the hill. They do certainly endanger it. You come round a corner and something's on your side of the road. You don't have much option and you don't get left with a lot of room."
Automobile Association spokesperson Dylan Thomsen said the Rimutaka Hill Road was the third riskiest stretch of road in the country and a lot of people didn't realise how hazardous it was.
He said motorcyclists do not have the same protection as cars, and drivers need to be aware of that.
"Since 2007 more than half of the fatal and serious crashes on the Rimutaka Hills have involved motorcyclists, and that's because there are a lot of motorcyclists who like riding the road. You've got a lot of risk factors and if you ever have something go wrong in a crash between a motorcyclist and a car it is always going to be the motorcyclist who is going to suffer far greater harm."
Mr Thomsen said the AA would like to see discussions take place to consider dropping the speed limit to 80km/h from 100km/h on the hill road.
