Transmission Gully chip seal causes havoc on first day open as commuter's windscreen cracks, police car gets stuck

After years of construction, blown budgets and missed deadlines, Transmission Gully has opened to the public.

The 27km motorway connects Wellington with the Kapiti Coast, but it's had mixed reviews from motorists on its first day.

Cars on Transmission Gully was a sight some didn't think they'd ever see. The $1 billion motorway finally opened to the public early on Thursday morning.

Many motorists were excited by the new opening and Mark Owen from Waka Kotahi NZ Transport Agency said it was "very pleased" with how the first day had gone.

Despite the excitement, it didn't shave too much time off the commute for some - even though it should cut travel time by up to 15 minutes. And not everyone enjoyed their maiden voyage.

"Part of it's like driving on corrugated iron and I now have a smashed windscreen [from] stones flicking everywhere. They've stuffed this one up," said Duncan West.

Owen said some of the pieces of the network do have chip seal surfaces, which will take time to roll in.

The gravel also caught out police, with one patrol car getting stuck in an arrestor bed designed to stop runaway vehicles.

That wasn't the only thing the police had to deal with. A small number of infringement notices were issued, most for speeding.

People are being reminded by the police to watch their speed and also asking drivers not to stop, as it's a motorway.

By Thursday afternoon the sp[eed limit was lowered in one area, as the chip seal continued to cause havoc.

Cellphone coverage is also a problem, with a number of black spots. Paul Brislen of the NZ Telecommunications Forum said that comes down to planning.

"Big infrastructure projects do need to consider cellphone communication at the start of the project rather than treat it as a nice to have added on at the end."

It's anticipated five or six cellphone towers are needed to fully cover the motorway.

"There are ducts in the ground that can be utilised for fibre so we're happy to keep talking with the telcos in terms of what their needs are," Owen said.

But the lack of connectivity hasn't stopped commuters from enjoying the road and capturing a moment of transporting history.