One person has been airlifted to hospital and two others have been injured after a lorry overturned on the M42 in Solihull.
The accident happened at about 1325 BST on Wednesday on the southbound carriageway between junctions five and six.
Volunteers from The Salvation Army and the Women's Royal Voluntary Service are providing bottles of water for motorists who have been held up in the tailbacks.
Sergeant Gary Higgs, from Central Motorway Police, said motorists who have been directed off at junction six of the motorway are being offered bottles of water.
"We've managed to clear the traffic between junction six and seven but prior to that traffic queues go back miles," he added.
"It does emphasise the need for people to carry a bottle of water with them in the car."