A MOTORIST has been killed in a three-vehicle collision on the M4 motorway.

The 23-year-old Canadian woman died this afternoon when the Nissan Micra she was driving collided with a Mercedes Sprinter Van.

Moments before, the navy blue van had collided with a Ford Focus as both vehicles travelled west between junction 16 and 17 at 3pm.

The van mounted the central reservation before landing on the eastbound motorway and spinning on its side into the light blue Nissan.

The dead woman's passenger, also female, was taken to Great Western Hospital with serious head injuries.

The male driver and passenger of the Mercedes van were also taken there with serious injuries, as was the male driver of the Ford who was treated for shock.

The eastbound motorway was shut between junctions 16 and 17 from 3pm to 7pm.

Minor roads north and south of the motorway were gridlocked.