The accident occurred at 11 o'clock on Saturday at the intersection of Blomstervägen and Get Johanna's väg in Avesta.
Ambulance, rescue services and police were called to the scene.
A man in his 80s is said to have been awake and talkative in connection with the accident.
"He was missing a helmet at the time of the accident and had injuries to his head and an arm.
It is unclear how serious the injuries are ", the police write on their website.
Police will draw up a report of a traffic accident where the driver, a man in his 20s, is suspected of having caused the accident by violating the duty to give way.