Thames Valley Police have arrested a man after it is alleged a car was driven the wrong way down the M40 southbound between High Wycombe and Stokenchurch. The motorway is now flowing freely.
Eyewitnesses have told ITV that a man drove his car at speed the wrong way down the M40, leaving a series of accidents in his wake.
The car, thought to be a Jaguar, was driven the wrong way between Junction 5 (Stokenchurch) and Junction 4 (Wycombe) this morning.
One eyewitness, Hans Cooper, said he believed the car was travelling at well over 100mph.
Marine accident investigators today urged authorities to tighten River Thames safety regulations in the light of the many activities on the river this summer.
The recommendation came in a report into a Thames collision between a high-performance rigid-hulled inflatable boat and a passenger ferry.