An American inventor based in the UK has won an international design competition.
Michael Chen, 28, won a £6,000 prize for his Reactiv cycle jacket, which changes colour as the cyclist brakes.
The inspiration for the jacket came from wanting to feel safer when cycling the streets of London.
Chen said: "I cycled round London in the dark wearing my first prototype. It was a £10 waterproof jacket with LEDs stuck on by gaffer tape."
He continued: "For the first time, I noticed that cars passed me more slowly, gave me more room, and that the drivers and passengers were even making eye contact."
How it works
The jacket uses an accelerometer to sense movement, changing the colour of LEDs on the back from green when accelerating, then to red when braking.
A tilt switch in the jacket also makes LEDs in the arm flash amber when the wearer lifts their arm to indicate a turn.
There were entries from 14 countries in the James Dyson international design awards in New York.
They included a tangle-proof sailing rope, underwear which can correct posture and a toilet which analyses waste.
Michael Chen will get a cash prize of £5,000 with the other £1,000 going to his former university in London.