The A24 is reportedly blocked northbound at Southwater.
An air ambulance is on the scene but police revealed it attended ‘as a precaution’.
A police spokesman said: “The first call came in at 15.47pm.
“It was a collision involving two vehicles and there were no serious injuries.
“It was not as serious as it first seemed.”
The road remains blocked whilst recovery of the vehicles take place. Stationary traffic has been reported at B2237 Worthing Road (Hop Oast Park and Ride roundabout), affecting traffic towards Horsham.
Further hold-ups have been caused by a broken-down vehicle near Dial Post on the A24 northbound. One of two lanes is reportedly closed.
Meanwhile, there is traffic near Pease Pottage and Roffey after a two-car collision.