Police Fire and paramedics rushed to the scene at Hilsea just after 5pm this evening after the incident outside the Green Farm Toby's Carvery at Hilsea.
Fire crews from Southsea and Cosham attended the incident as it was reported that the woman was entrapped within the bus.
Paramedics stabilised the woman at the scene who is believed to have received serious leg and head injuries, before she was flown to hospital.
Witnesses described the woman as having serious injuries after she collided with the windscreen of the bus.
The 59-year-old woman has been flown by the Hampshire and Air ambulance to Southampton General hospital with life threatening/changing injuries. The road is likely to remain closed for some time whilst accident investigation work takes place. A hard road closure has been put in place by Police.
Police have closed the road both ways whilst they carry out investigation work.
Officers at the scene are advising drivers in the area have been warned to find alternative routes.
More to Follow.