The eastbound carriageway of the M4 motorway was closed for two hours on Monday morning after three coaches crashed in Wiltshire.
The accident at 1050 GMT between junction 15 and Membury Services on the Berkshire border, caused long delays.
Lanes two and three reopened at 1245 GMT and the whole motorway had reopened by 1600 GMT.
Two coach drivers were hurt in the collision but their injuries are not thought to be life-threatening
No passengers
A single passenger in one of the coaches and the female driver of a Nissan Micra which was also involved, both broke their legs.
It is believed that there were no other passengers on the buses at the time.
Eyewitnesses said all three coaches appeared to be brand new.
They were being delivered to C I E Tours International in Surrey, a North American company which runs tours of Britain and Ireland.