A motorcyclist has died and another is in a London hospital with serious injuries to his head and pelvis after a crash on the M20 in Kent.
The crash, involving two bikes, happened on the coastbound carriageway near the M25 interchange at Swanley at about 1540 BST on Friday.
Kent Police said there were no cars involved in the crash.
A spokesman said the two motorcycles were travelling together when the lead rider came off his bike.
The second rider collided with him.
The lead motorcyclist, believed to be a man in his 50s from outside Kent, was pronounced dead at the scene.
The second rider was taken to hospital by air ambulance. He is in a serious but stable condition.
South East Coast Ambulance Service said six ambulances and rapid response vehicles were sent to the scene.
Drivers on the motorway faced long delays, with the carriageway remaining closed until about 2100 BST.
"I would like to thank those motorists who were stuck in the tailbacks behind the incident for the patience and understanding they showed while we investigated this serious collision," said Chief Insp Martin Cunningham.
"We would like to hear from anyone who may have witnessed the collision or may have any information which could help this investigation".