The three vehicle collision on the M5 between junction 15 at Almondsbury and junction 14 at Thornbury, had shut one of the three lanes.
National Highways South-West reported that delays initially increased by 30 minutes beyond usual travel times.
The scene was cleared, and all lanes were reopened, with residual delays of at least 20 minutes remaining.
An Avon and Somerset Police spokesperson said; “We received a 999 call to reports of a road traffic collision on the southbound carriageway of the M5 between junction 14 (Thornbury) and junction 15 for Almondsbury.
“Three vehicles were involved in the collision.
“Two people involved in the collision were taken to hospital with injuries which are not thought to be life-threatening or life-changing, and a third was assessed by paramedics at the scene.”