PEDESTRIANS crossing the road in Hong Kong may now find themselves bathed in a red glow after authorities installed a device reminding the public to obey traffic lights.


Too often, Hong Kongers walk into traffic because they are distracted by their smartphones, Alex Au, chief engineer of the city's transport department, said Thursday.


"For people looking down at their phones, we have found another way to let them know there is danger," Au said on a radio program.


Au added that in the first half of the year, four of the seven fatal incidents occurring on Hong Kong's road crossings were related to pedestrian behaviour.


"Maybe (the device) can help save lives," Au said.


The new device works in sync with a traffic light and projects a red hue from above when pedestrians need to stop.


It is being tested at four road crossings across the city, and officials will review in six months their effectiveness in curbing inattentive strollers and unrepentant jaywalkers.


Near a busy mall in Causeway Bay, one of the city's most popular shopping districts, the sudden appearance of a red spotlight was greeted with approval -- and occasional confusion.


"I personally don't do this, but I have noticed people ignoring road conditions because they were glued to their phones," said a researcher surnamed Kwok.


"I think people will notice the colour even if their heads are down."


But, surrounded by bright signage and billboards, another woman said she had no idea what the glow from above was supposed to mean.


"When I walked over just now, I didn't know what it was doing," she told AFP.


Others -- including the handful of jaywalkers spotted at the scene -- may see it in an altogether different light.


"If people really want to ignore (the red light), that's what they'll do," said a clerk surnamed Chung.


"You can't stop them."


In recent years Hong Kong has recorded around 2,000 to 3,000 pedestrian casualties in traffic accidents per year in a population of 7.4 million.