LANE CHANGING ON TWO LANED MOTORWAYS

A STUDY IS MADE OF VOLUNTARY LANE CHANGING PROCESSES ON THE FREE SECTION OF TWO-LANE MOTORWAY CARRIAGEWAYS. INFORMATION ON THE CHARACTERISTIC FEATURES OF MOVEMENT AND POSITIONING WAS OBTAINED BY A SERIES OF CONSECUTIVELY PLACED INDUCTION LOOPS. LANE CHANGES ARE CLASSIFIED: FOUR LANE CHANGING TYPES FOR CHANGING TO THE OFFSIDE AND TWO CHANGING TYPES FOR MOVING TO THE NEARSIDE. REGRESSION ANALYSIS IS CARRIED OUT IN ORDER TO DETERMINE THE RELATIONS BETWEEN THE VARIOUS CHARACTERISTIC FACTORS. THERE IS A RELATION BETWEEN LANE CHANGING BEHAVIOUR AND LANE DISTRIBUTION. SMALLER HEADWAYS ARE TAKEN ON THE OVERTAKING LANE COMPARED WITH THE NEARSIDE ONE, SO THAT UNEQUAL LOADING OF THE TWO LANES OCCURS IN SECTIONS OF HIGH TRAFFIC DENSITY. LANE CHANGING REPRESENTS A CONSIDERABLE POTENTIAL DANGER IN MULTI-LANE TRAFFIC FLOW. MAXIMUM LANE CHANGING FREQUENCY IS 600 LANE CHANGES PER HR PER KM IN TRAFFIC DENSITY OF 2000 VEHICLES/H. INCLUDED IN THE CONSIDERATIONS IS THE FREQUENCY OF OVERTAKING AND ITS INTERRELATION WITH THE LANE CHANGE FREQUENCY. IT IS SHOWN THAT AS A RULE EVEN IN LOW TRAFFIC DENSITY MORE THAN ONE VEHICLE IS PASSED IN A SINGLE OVERTAKING PROCESS. THE MATHEMATICAL RELATIONS FOUND SERVE TO FORMULATE THE BEHAVIOUR OF LANE CHANGING IN A SIMULATION MODEL OF ROAD TRAFFIC FLOW.