The Sureté du Quebec said that around 1 a.m. a driver speeding south on the bridge struck another vehicle.
A third vehicle then hit the car that suddenly ground to a halt.
A woman was badly hurt and rushed to hospital, but she is expected to survive her injuries.
Police say they arrested a 30-year-old man and they are recommending charges of dangerous driving causing injury.
The southbound bridge was closed overnight but all lanes re-opened at 5:30 a.m.