Kaiapoi High School has installed road signs outside its school depicting teenagers with their heads down, looking at their cellphones, in the hope of slowing down traffic.

Kaiapoi's creative speed sign is expected to slow traffic. Source: 1 NEWS

State Highway One, with a 100km zone, ends just before the school on Ohoka Rd.

Kaiapoi principal Bruce Kearney Source: 1 NEWS

Principal Bruce Kearney told ONE News that planning for the two signs, in partnership with Waimakariri District Council, took about a year.

The school hopes the signs will create awareness of cars speeding past the school towards the motorway, and when leaving the motorway in the other direction, he said.

"So if they don't speed up, it's a win for us," he said.

"Just for 15 minutes a day, we wanted awareness."

Waimakariri District Council Ken Stevenson said there's been feedback on the signs from within council and from members of the community.

"They certainly have been noticed.

We've got a bit of a creative bunch and that was the idea that we came up - Ken Stevenson

"We've got a bit of a creative bunch and that was the idea that we came up with for that site," he said.

Mr Kearney says other high schools are free to adopt the new-age signage.

"It just makes it a little bit more different.

"They should go for it."