Vehicle control system and control method: Determining map data and autonomous vehicle control

A control system for a host vehicle 10 operable in an autonomous mode is configured to receive first environment data and second environment data. The first environment data is indicative of a navigation characteristic associated with a potential obstacle 54 relating to an area 50 within which a host vehicle is operated at a first time. The second environment data is indicative of the navigation characteristic relating to the area at a second time different from the first time. A controller determines map data relating to the area in dependence on the first environment data and the second environment data. When subsequently navigating the area to a navigation goal in an autonomous mode, the control system utilises the map data to autonomously navigate the host vehicle. The map data may not be determined again where the host vehicle re-enters the area in less than a predetermined threshold time. The navigation characteristic may relate to a presence or absence of the potential obstacle and the map data can be determined when an obstacle appears or disappears in the area. Obstacles can be classified as stationary or dynamic.