Australia's two largest cities are trying out in-ground traffic lights so that even the most absorbed phone user will know when it is safe to cross the road.

The hard-to-avoid lights are designed to combat an increase in pedestrian deaths, which the authorities believe are linked to people using smartphones while walking.

In separate trials, Melbourne has installed green and red lights on the footpath, which flash when the road signal is about to change, while Sydney is trying out a less intrusive system, with the lights turning red only when the traffic signals change.

The trials follow concerns about pedestrians crossing busy roads in the city centre without looking up from their phones. The authorities say that, in many cases, pedestrians do not even realise they have crossed against the traffic.

Melbourne started its trial on Monday, installing lights along the footpath in the central business district at the intersection of Little Collins Street and Swanston Street.

FOOT TRAFFIC

• In New South Wales, 74 pedestrians were killed last year, up from 61 in 2015

• About 1,100 pedestrians in New South Wales are seriously injured each year

• In Victoria, 40 pedestrians died last year, up from 33 in 2015

• About 500 pedestrians in Victoria are seriously injured each year

• About a third of Australians purportedly use their phones when crossing the road

The state government of Victoria said road safety experts will examine the impact after 12 months and decide whether to install further lights. The trial will cost about A$120,000 (S$127,000).

The authorities believe phone use is leading to an increasing number of accidents, though the exact number of casualties associated with phones is unknown.

In New South Wales, 74 pedestrians were killed last year on the state's roads, 13 more than in 2015. Another 1,100 pedestrians are seriously injured each year.

Minister for Roads and Road Safety Luke Donnellan said in a statement on March 27: "There is growing evidence that using your phone as a pedestrian can lead to serious injuries, so we need everyone to focus on their surroundings and not their mobile phones."

The trial in Sydney began last month at two locations in the city centre at the corners of Pitt and Goulburn streets, and Hay and Dixon streets.

So far, Sydney residents appear to have welcomed the new lights. "We don't have to look at the green light," Mr Ricky Xu, a mortgage broker, told The Sydney Morning Herald. "Most people are checking their e-mails (while) waiting for the lights."

The trial follows the introduction of similar foot traffic lights in German cities Cologne and Frankfurt, and in Bodegraven in the Netherlands. In Australia, the Gold Coast in the state of Queensland is also considering a trial. The Sydney trial will cost about A$380,000.

A New South Wales government spokesman told The Straits Times that other safety measures are also being introduced, including giving greater priority to pedestrians to prevent "green-on-green" crashes, where drivers and pedestrians simultaneously receive a green light. This can include delaying the drive signal so that pedestrians set off first. In addition, the state has introduced 40kmh speed limits in busy areas.

Research has found that using phones while walking can affect a person's ability to keep a straight line or a steady pace.

Police in several Australian states have been targeting jaywalkers and pedestrians who fail to take sufficient care while walking. Some road safety advocates - including numerous state politicians in the United States - have called for bans on using phones while walking.

Australian law lecturer Mark Giancaspro, from the University of Adelaide, said a ban would be difficult to enforce, but could help to change attitudes. "Perhaps legislative intervention is one step towards tackling this cultural obsession with technology, and might make pedestrians realise that no call, text or e-mail is worth dying for," he wrote on The Conversation website last year.