California Partners for Advanced Transportation Technology

This report provides interim results on the design of interfaces between automated highways and conventional street systems. The purpose here is to identify the strategic issues in interface design, and to provide preliminary analysis on just one of these issues (separation between highway entrance and exits). Future research will explore a full set of strategic issues in greater depth. The central concept explored in this report is how to design a roadway system that comprises multiple layers, some of which are designed for the purpose of accessibility, and others of which are designed more for the purpose of speed and capacity. With multiple layers, efficient functioning of the roadway system depends on creating effective roadway interfaces. The interface between an automated highway system and conventional roadways presents new challenges for interface designed, which are explored in this paper.