At head of title: National Cooperative Highway Research Program.

The progress that has been made in developing the positive guidance concept is documented, and the meaning of positive guidance, the philosophy of driver performance upon which it is based the nature of the driving task at those locations where positive guidance is applicable, and a procedure for its application are discussed. This report describes what must be done to improve the information system at hazardous locations. Positive guidance which is an information system matched to the facility characteristics and driver attributes, is based on the premise that a driver can be given sufficient information where he needs it and in the form that he can best use to avoid hazards.

Expectancy relates to a driver's readiness to respond to situations, events, and information in predictable and successful ways. This report describes the concept of driver expectancy in the context of the driving task, and provides examples of expectancy and expectancy violations. It includes a procedure for identifying general and specific expectancy violations to enable engineers to develop remedial treatments to deal with expectancy problems.