Emergency services attended the incident on Junction 4 at about 4.40pm on Sunday.
The smash involved a 4x4 which went down an embankment off the eastbound slip road and smashed into a tree, causing the roof to crumble.
West Midlands Ambulance Service (WMAS) confirmed a man, woman, boy and girl "escaped serious injury" and were taken to Wolverhampton's New Cross Hospital for further assessment.
The ambulance service sent two ambulances and a paramedic officer to the scene. West Mercia Police were on scene as well as the Hazardous Area Response Team, which came across the accident while returning from another incident.
A WMAS spokesman said: "Two adults and two children have escaped serious injury despite their 4x4 vehicle going down an embankment and colliding with a tree, causing significant damage to the roof.
"Two ambulances and a paramedic officer were sent to the scene, but were assisted by the Hazardous Area Response Team, which came across the incident while returning to their base after another incident.
"The man, woman, boy and girl were taken to New Cross Hospital for further assessment."