A motorist may say that one road is ‘nice’ to drive on while another is not. It is most likely that a reason for this opinion would not be forthcoming. It is probably like a preference for roast potatoes. They are simply liked or not. The designer may thus be in the position of having to delve into the motorist’s subconscious to establish the origin of the stated preference to establish a rationale whereby future designs could qualify for being ‘nice’. However, it is reasonable to speculate that drivers’ opinions are based principally on what they see and, to a lesser extent, feel. The latter refers to forces acting on the human body such as those resulting from braking, acceleration or horizontal curvature.