TRAFFIC FLOW IN TUNNELS

Abstract

IN THE ABSENCE OF A SUITABLE DETERMINISTIC TRAFFIC FLOW MODEL, CAPACITY OF INDIVIDUAL SECTIONS OF SINGLE-LANE ROADWAYS MUST BE INFERRED FROM THE OBSERVED CHARACTERISTICS OF THE TRAFFIC FLOWING THROUGH THE SECTIONS. IN THIS CASE, THE FLOW-CONCENTRATION CHARACTERISTICS OF KINEMATICS ARE USED. VARIOUS FLOW-CONCENTRATION RELATIONSHIPS HAVE BEEN PRESENTED IN TRAFFIC ENGINEERING LITERATURE, AND OBSERVATIONS IN SEVERAL TUNNEL ROADWAY SECTIONS ALSO PRODUCED VARIOUS RELATIONSHIPS. IT IS SUGGESTED THAT THESE CHANGING RELATIONSHIPS ARE RELATED THROUGH THE EFFECT OF BOTTLENECKS. THE KINEMATIC WAVE ANALOGY OF LIGHTHILL AND WHITHAM IS COMPARED WITH EMPIRICAL DEVIATIONS FROM THE THEORY. FINALLY, THE IMPORTANCE OF STIMULATING FURTHER THEORETICAL RESEARCH ON TRAFFIC FLOW IS EMPHASIZED. /AUTHOR/