The A27 Arundel Road has been closed both ways at Crockhurst Hill after a ‘head-on collision’ between a lorry and a van.
The 7.5 tonne lorry overturned after colliding with the van on the corner, said Worthing fire station manager and district commander Roy Barraclough.
Both drivers were medically trapped inside the vehicles and had to be released, he said.
The drivers were taken to hospital but were believed to have suffered minor injuries, Mr Barraclough said.
An air ambulance was called to the scene but was not required to assist, he added.
Two dogs were also released from the lorry.
Mr Barraclough confirmed that they had been taken to Grove Lodge Vets in Worthing for a check up and to spend the night.