Highway safety begins with the basic geometric design of the highway to meet the driver's need. The sources of information available to the driver are examined and it is suggested that the formal information system (signs, signals and markings) is secondary in importance to the driver's perspective view of the roadway. The concept of driving expectancy is defined for engineering application. The application of this concept requires that the actions of a design driver be defined in general terms. It is logically concluded that the design driver should be a driver who is unfamiliar with the roadway; also a set of driving postulates is presented. The need for co-ordination of geometric design features and the roadway information systems is stressed.
Abstract