Terminus Road in Chichester has been closed after a collision between a car and a bicycle.
A Sussex Police spokesman said officers and the ambulance service had been called just before 5.30pm to reports of a collision.
Terminus Road has been closed both ways while the emergency services attend the scene.
Traffic is queuing in both directions from the junction with Stockbridge Road and the A27 at the Fishbourne Roundabout.
South East Coast Ambulance Service has been contacted for more information.