The new $630 million Kapiti Expressway was built to cut down travel time and ease congestion into the capital, but commuters say it is having the opposite effect.
The expressway was opened last month, but the traffic issues it has created might not be fixed until the Transmission Gully project is finished in 2020.
Paraparaumu Beach resident Rob Scotcher travels to Wellington on the expressway every day.
He said the new stretch of road could sometimes add an extra 30 minutes onto his commute, and he put that down to the multiple merging points.
"There's a lot of traffic that's going into Wellington these days, and we have a number of choke points. The point about those choke points is that they all have something in common, and they all demand drivers merge," he said.
He said the point at Mackays Crossing was a particular nightmare, and motorists needed to realise that trying to push through quicker was not going to work.
"You see people shaking fists, I've witnessed banging their cars with their fists because they don't want to relinquish their spot. What they forget is actually that just causes problems further down the road for everyone."
Mr Scotcher said the expressway was generally great, but it was those small hold-ups that were causing the delays.
Wellington City councillor Chris Calvi-Freeman raised the problem with the Regional Transport Committee yesterday.
He said he had received a lot of public feedback from people who were annoyed about the slower commute time.
"Basically what they're saying is that once upon a time you could leave for work pretty early in the morning from Kapiti, and get a fairly predictable run into Wellington. They're finding now that even leaving quite early, 6.30, 7am, [they] are getting caught in long tailbacks."
Mr Calvi-Freeman said it would be hard for changes to be made with the Transmission Gully project already under way.
"We're in the period now where we're between the opening of the Kapiti Expressway and the opening of the Transmission Gully, which is still three and a half years away, and I don't think any letters to NZTA are going to make any real difference to the way motorists are behaving."
Kapiti Coast District mayor K Gurunathan said people needed to wait for Transmission Gully to open in 2020.
"This will take traffic from MacKays Crossing where the current problems are and then you'll have a smooth ride right through to Wellington.
"It [the delays] won't stop anytime soon. Until Transmission Gully is open, there will be other works associated with Transmission Gully which will slow down the traffic in other part of the current state highway heading to Wellington, that's for sure."
In a statement, NZ Transport Agency highway manager Neil Walker said merge points were affecting travel times, and it was considering painting road lines to see if that would make any difference.
He said NZTA would report back to the Regional Transport Committee in May.