Travellers will be able to celebrate State Highway 1 reopening with a nostalgic toot in the tunnels south of Kaikōura. (File photo)

Whether it's a couple of toots or a long loud blast, motorists heading south will soon be punching the horn through Kaikōura's tunnels once more.

Travellers gearing up to drive from Blenheim to Christchurch for the first time since the 7.8-magnitude earthquake are reminiscing over family traditions associated with State Highway 1 journey.

Some just toot for the echo, some toot in memory of their forebears who tooted before them, but all the toots will celebrate driving from Blenheim to Christchurch along the coast for the first time in a year.

Blenheim retiree Brenda Price will be tooting in the tunnel for the first time since last year's earthquakes, driving to Sefton, north of Christchurch, for her grandson's birthday next week.

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STUFF Large slips blocked the tunnels south of Kaikōura after the earthquakes, but they were cleared in December 2016.

"I'm dying to see the highway now. I just can't wait," Price said.

Price and her parents had been tooting in the tunnels for at least 60 years, she said.

"I've done it all my life. If I had $5 for every time I've tooted in those tunnels I'd be a millionaire. My husband always growls at me. I think he thinks it's just rude. But I've done it my whole life and it just became a tradition.

EMMA DANGERFIELD The type of toot in the tunnels south of Kaikōura varies between families. (File photo)

"We just do a 'toot toot'. But if I had my way it would be a big long toot."

Blenheim mother-of-three Cherayn Bryant said her family tradition was to do several short toots followed by a long toot - and her children would wind down the windows and shout things.

"We always have to yell something to do with where we are going, it might be someone's name. My dad always got us to do that. And if there were too many cars we would just wait until they had gone."

For Bryant, the tunnels reminded her of summer holidays on the Kaikōura coast, she said.

"We must have tooted in the tunnels hundreds of times. I remember you'd always want to be awake for the tunnels. And you had to have the window wound down.

"I don't know where it came from, we have friends and family who do it too. It's a Kiwi sort of thing to do, or South Island at least. I hope my kids will do it too."

Bryant's family was heading to Christchurch on Saturday for a concert, but they decided they would take the alternate highway instead of SH1, Bryant said.

"But next Wednesday we'll be coming home that way. We'll stop where we can and have a look at what has changed. It was sad not to be able to drive down the coast after the earthquake. It was a regular road trip, so I can't wait to see the tunnels again."

A New Zealand Transport Agency spokeswoman urged drivers who toot in the tunnels to exercise caution.

"People will be easily distracted on the new road, and there will be lots of people travelling from other countries who aren't aware of the tradition. People should use their common sense, and be considerate of others on the road."