The Oxford Bus Company vehicle came off the road at around 02:45 on Friday morning.
Injuries included cuts, bruises and broken bones and the South Central Ambulance Service (SCAS) declared it a “major incident” due to the number of people who were injured.
The Junction 7 slip road is currently closed.
A statement from the SCAS reads:
We were called at 02.45 this morning (30/12/16) following reports of a coach operated by the Oxford Bus Company having come off the slip road on the M40 northbound at Junction 7 (Milton Common, Thame).
South Central Ambulance Service declared this a major incident due to the number of patients involved and attended the scene with our colleagues from Thames Valley Police and Oxfordshire Fire and Rescue Service. There was thick fog in the area at the time of the accident which also presented challenges to the emergency services getting to the scene.
The male coach driver and 16 adult passengers (mixture of male and female) had sustained a variety of minor injuries, such as cuts, bruises, broken bones, etc., and all 17 patients were taken to the John Radcliffe Hospital in Oxford.
At the scene, we had six ambulances, a rapid response vehicle, three ambulance officers (two bronze and one silver), a BASICS Doctor and the Trust’s Hazardous Area Response Team. We also sent a Silver Officer to the emergency department at the John Radcliffe Hospital to assist with the arrival of this large volume of patients.
The Met Office has issued yellow fog warnings for much of Southern England, calling driving conditions “difficult”.
Its Chief Forecaster said: “Fog and freezing fog patches are locally dense with visibility less than 100 metres in places. Combined with sub-zero temperatures, there is also a risk of icy patches on some untreated surfaces.
“This fog will only slowly lift and thin today, likely lingering into the late morning or afternoon in some places, most likely over parts of East Anglia and southeast England.”