Police are appealing for information, including dashcam footage, following a fatal collision eastbound on the A27 between Fontwell and Arundel.
The collision happened just before 9.25pm on Monday, January 16.
A car, a white Porsche, collided with a stationary police car who was assisting with a broken down vehicle.
Sadly the driver of the Porsche was pronounced dead at the scene.
The road remains closed in both directions while investigating officers continue their enquiries and ensure the road is safe for other vehicles.
It is not yet known when the road will reopen.
Anyone with information or dashcam footage which could assist officers with their investigation is asked to email it to collision.appeal@sussex.police.uk quoting Operation Burley.