A man has died in a crash involving a coach, a lorry and two cars on the M5 in Gloucestershire.
The 30-year-old, from Birmingham, was driving one of the cars, which collided near junction eight at about 0700 GMT.
Next of kin and the coroner have been informed.
Three of the 18 passengers on the single-decker Megabus coach, which was travelling from Cardiff to Leeds, were taken to hospital but their injuries are not life-threatening.
A police spokeswoman said the coach, collided with an articulated lorry on the northbound carriageway and the lorry crossed on to the southbound carriageway.
The lorry then collided with a Ford Fiesta, which then hit a Rover.
The driver of the Fiesta died at the scene.
A 69-year-old man from the Birmingham area who was driving the lorry was taken to a hospital in Worcester with minor injuries.
The Rover driver, a 27-year-old man from Pembrokeshire, and his passenger, a 26-year-old woman from Worcester, both received minor injuries and were treated at Cheltenham General Hospital.
Three of the 18 passengers on the coach were also taken to Cheltenham General Hospital with minor injuries while the rest continued on an alternative coach.
A spokesman from Megabus said: "It is understood there was heavy fog at the time of the accident and there is extensive damage to the coach.
"Safety is our absolute priority and we will be carrying out our own internal investigation, as well as assisting the police in any way that we can with their inquiries into the accident."
In a separate crash, 17 people needed hospital treatment after an Oxford Tube coach overturned as it left the M40 on Saturday night.
Five of the injured needed surgery, mostly for broken bones.