Correlation of Future Vehicle and Highway Design

Vehicle characteristics most relevant to highway design problems are performance, fuel economy, brake deceleration, and dimensions. A review of these characteristics since 1930 shows that there have been significant long-term trends, but the changes have been moderate and relatively uniform in rate. They have largely consisted of many refinements and design changes that have improved the safety, comfort, ease of operation, and fuel economy in frequent small steps. Passenger cars that are closely similar to the current (1962) small cars have been available from one or more makers each year for more than 30 yr and small cars do not confront the highway designer with a new type of vehicle. The larger and heavier cars of 1930 were larger and heavier than their successors in 1961. The trend of reduction in driver eye height that has accompanied the overall reduction in car height appears to have leveled, and no further significant changes are anticipated. Passenger cars for the next generation will be refined descendants of current models, and they will continue to provide safe and effective transport on the existing highway system.