One side of the M55 was closed after a car hit the central reservation, emergency services said.
Police and paramedics were called to the motorway between junctions three and four westbound at around 4.20pm today.
Traffic was diverted off at Kirkham, with police warning motorists to find alternative routes.
The ambulance service said they took a woman - feared to have collapsed behind the wheel - to Blackpool Victoria Hospital.
Her condition was not immediately known, though police officers initially responded to 'minor injuries', a spokeswoman said.
One driver described miles of tailed back rush hour traffic, with Highways England saying there had been some 'barrier damage'.
The motorway was re-opened by 6.35pm, police said.