'It's a horrible part of our job and it's a part we do too often'- Policeman hopes to quell fatal crashes

Tired of telling families their loved ones have died in car crashes, a Canterbury police officer has an idea to reduce the number of serious accidents.

After a fatal crash in Rakaia during 2014 and an 18 month bureaucratic battle, Sergeant Dan Harker can now trial his warning signs.

Car-detecting signs will be erected at four notorious intersections throughout Selwyn, south of Christchurch.

"I'll never know if I save a life or not but I suspect we're going to have pretty good success with this," he told ONE News.

"You're going to some stranger's house in the middle of the night or during the day and you're going to give them some news that they never want to hear, and that news is going to destroy them, and it's a horrible part of our job and it's a part that we do too often."

NZTA said the 484 crashes at intersections in Selwyn between 2009 and 2013 came at an estimated social cost of nearly $100 million.

When the trial is over the transport agency will crunch the numbers and reveal the impact of the detection signs, with a possible roll out to the rest of New Zealand's intersections.

Sergeant Dam Harker has invented cost-effective warning signs that are to be trialled around Selwyn intersections. Source: 1 NEWS