It happened on Chester Road in the Castle Vale area of Birmingham at just before 9.10am this morning.
An ambulance came across the incident four minutes after the call and was backed up by a second ambulance, the Midlands Air Ambulance critical care car, a paramedic officer and the Warwickshire and Northamptonshire Air Ambulance with a doctor on board.
A West Midlands Ambulance Service spokesman said: “On arrival, ambulance staff found a woman who had suffered very serious injuries.
“She was treated on scene by ambulance staff and the doctor before being taken on blue lights to the major trauma centre at Queen Elizabeth Hospital Birmingham by land ambulance; the doctor travelled with the ambulance.
“The woman driving the car was shaken but wasn’t injured.”