Sussex Police was called at 8.40am this morning to the ambulance station in Chichester Road, Bognor Regis after the vehicle crashed through the bay doors and drove through the building before colliding with an internal wall and coming to a stop.
According to a police spokesman, no staff members at the station or members of the public were injured. The driver fled the scene, and their injuries are unknown.
Police officers were searching for the driver 'to ensure they are safe and well', the spokesman added.
At 3pm, a police spokesman said the driver was arrested at 11.57am at the scene of the incident, and is in custody.
They could not confirm the age or gender of the driver, what crime they were arrested in connection with, nor if the vehicle had been stolen.
West Sussex Fire Rescue Service has checked the building is structurally sound and the vehicle has been recovered.