A man who has spent months working security on State Highway 25A in Coromandel says he's extremely relieved the Taparahi Bridge was able to reopen ahead of schedule.

The new 124-metre Taparahi Bridge opened on State Highway 25A yesterday morning.

The Kopu Hikuai section has been shut since January due to structural cracks in the road, which was eventually washed away by heavy rain.

Initially slated to open next April, the reinstatement of the highway will take hours off trips for those accessing the Coromandel Peninsula.

Tairua resident John Smith spent the last seven months working security near the job site.

"I've worked at a security gate keeping out the people who thought the road was either open or who wanted to go and have a look, so that the people could do their job and get this bridge open and the road open."

The maps built into rental cars continued to say that the road was open when it wasn't, he says.

"And people just ignore the fixed road closed signs that they drove past thinking 'well my map says it's open so it must be'."

The new bridge Photo: Supplied / Waka Kotahi NZTA.

John says it was an impressive feat to get the road reopened, which involved the use of 100 tonne cranes, boring machines and dozens of trucks arriving at the site every day to take material away.

In order to be able to get to the bridge itself, the road had to be reopened and many people did not realise just how badly damaged it was, he says.

While on duty, John had a range of ways of keeping himself occupied.

"I took along some gym equipment and did workouts on the side of the road, I read a lot of books obviously, and yeah, talked to people who turned up."

He also practised playing the didgeridoo but is still not very good.

John's wife Maree put on a celebration street party in Tairua to mark the opening.

He says it was great to see everyone happy, with people enjoying themselves and having fun.

Despite John earlier this year posting on Facebook that there was no way the road would reopen this year, he says he and the community are extremely pleased that it has.

"As a business owner it's been extremely tough and not only for us but for all the businesses, the hospitality, the local grocery shops, the service station, everyone's struggled to get through the last nine to ten months."

John will be driving over the road on Christmas Eve to get to Auckland for a family Christmas and it will save at least an hour and a half travel time.

-RNZ.