One appliance and crew from High Wycombe, one from Beaconsfield and one from Maidenhead attended, along with an officer.
One man, one woman and one girl were released, uninjured, before they arrived.
One man and two women were released suffering minor injuries before they arrived. They were cared for by South Central Ambulance Service.
The firefighters made the scene safe.
Thames Valley Police and Highways England were also in attendance.