Perception of highway traffic signs and motivation

Nine subjects were instructed to drive as safely as possible over a highway route of 257 km and to name all the traffic signs base all along the route. These subjects were able to report approximately 97% of the signs on the entire route and virtually all of the signs in the nonurban, not intersection areas, while driving safely in committing no traffic violations. It was concluded that earlier experimental results pointing to the relative inefficiency of highway signs are probably primarily due to the deficient motivation of drivers to utilize them.