Zombie warning baffles Boulder

A highway sign in the US warned motorists that zombies were ahead.

Baffled drivers were on the look-out for the undead in Colorado after the sign flashed the bizarre warning.

According to road officials the sign was supposed to state: "Shoulder work Feb 28 through June" but someone opened the unlocked control panel to write "ZOMBIES AHEAD" instead.

Rick Barron and his wife were driving to the airport when they saw the sign.

He said: "My first thought was, 'Did that really say Zombies Ahead?' And my second thought was 'I've been in Boulder almost 30 years. If there were naked zombies riding bicycles with pumpkins on their heads, I guess we'd be used to it."