The 4x4 hit the crash barrier and flipped onto its side shortly before 4pm on Wednesday.
West Midlands Ambulance Service sent three ambulances and two paramedic officers to the scene and treated four patients who were all taken to the Royal Shrewsbury Hospital.
A spokesman said the driver suffered "potentially serious injuries".
A second man and two women were all taken to hospital for further assessment but their injuries are not believed to be serious.
The road was closed westbound between junction 6 and 7 for more than an hour and drivers faced major delays of up to two hours.
West Mercia Police and Highways England were also on scene.