Police are investigating after a man was discovered with a head injury at the junction of Chorley New Road and Chorley Old Road in Bolton.
Officers were called to the street by the ambulance service shortly after 2am on Friday 14 July 2014.
The man, 49, has been taken to hospital in a critical condition.
The road has been closed and enquiries are ongoing to establish how the man came by his injuries.
Anyone with information should call police on 101 or the Crimestoppers anonymously on 00800 555 111.