Motorists faced severe delays earlier when a lorry caught fire in Oxfordshire.
One lane was closed on the M40 between Banbury and Brackley just before the morning's rush hour.
Tailbacks stretched to up to eight miles.
More top news
United in silence. People in the Thames Valley came together today to remember those killed and injured in the Manchester terror attack.
The South stood silent today - from Brighton to Basingstoke - to remember those killed and injured in the Manchester terror attack.
After the deaths of seven people at Camber Sands last summer, lifeguards will be patrolling there for the first time from this weekend.