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
The Airports Commission is to publish its report and recommendations on whether an extra runway should be built at Gatwick or Heathrow.
Wednesday morning's weather for the east of the region
Wednesday morning's weather for the west of the region