Future path and tangent point models in the visual control of locomotion in curve driving

Studying human behavior in the natural context of everyday visual tasks--including locomotor tasks such as driving--can reveal visual strategies or even suggest underlying visual mechanisms. This paper reviews empirical and theoretical work in the past 20 years (1994-2014) on the visual control of steering a vehicle along a winding path-one of the most comprehensively studied forms of visually guided locomotion in humans. The focus is on on-road studies of visual behavior and what they can reveal about the visual strategies in curve driving. Theoretical models and results from simulator studies are discussed where they have direct relevance to the interpretation of on-road data. For the past 20 years, the point of departure in studies of curve driving has been tangent point orientation, and tangent point models (models based on tracking the tangent point) have become established as the default account of how vision is used in curve negotiation. More recent studies have questioned the generality of the tangent point hypothesis, however, arguing that in addition to (or instead of) the tangent point, drivers target visual reference points on their future path. Ecological validity of real-world studies often comes at the cost of methodological challenges that make the data difficult to interpret in terms of underlying mechanisms, and the limitations of existing data and the complementary roles of real-world and laboratory studies are discussed.