STUDIES OF REQUIRED LENGTH OF ACCELERATION LANES IN ACCORDANCE WITH THE LAYOUT OF THE RAMPS (RADIUS AND GRADIENT) OF MOTORWAY ACCESS ROADS IN CONGESTED AREAS, BY MEANS OF A SIMULATION MODEL AND EXISTING AND MEASURED DATA ON TRAFFIC BEHAVIOUR

UNTERSUCHUNGEN ZUR BESTIMMUNG DER ERFORDERLICHEN LAENGE VON BESCHLEUNIGUNGSPUREN GEMAESS DEN AUSBAUFORMEN DER RAMPE (RADIUS U.GRADIENTE) VON AUTOBAHNEINFAHRTEN IN BALLUNGS RAEUMENMIT HILFE EINES SIMULATIONSMODELLS UND AUFGRUND VORHANDENER UND GEMESSENER DATEN ZUM VERKEHRSVERHALTEN

AS A COMPLEMENT TO THE RESULTS OF A CONTINUING FOREIGN RESEARCH PROJECT (1V,105=3.708; IRRD NO.039057) AND A SIMULATION MODEL DEVELOPED WITHIN THIS FRAMEWORK FOR THE ENTRY PROCESS ON MOTORWAYS,A STUDY IS TO BE CARRIED OUT TO DETERMINE THE LENGTH OF ACCELERATION LANE NECESSARY WITH VARIOUS TYPES OF RAMP DESIGN FOR COPING WITH A DEFINED VOLUME OF TRAFFIC.SINCE UP TO NOW IT HAS BECOME APPARENT THAT MATHEMATICAL EQUATIONS OF HEADWAY,SPEED AND VEHICLE TYPE DISTRIBUTIONS ARE LESS SUITABLE FOR INPUT TO THE SIMULATION MODEL,IT WILL NOT BE POSSIBLE TO VARY THE TRAFFIC VOLUMES ON THE LANES CONTINUOUSLY.THEREFORE AT MOTORWAY ENTRY POINTS WHERE THERE ARE HIGH ENTRY SPEEDS AND A LARGE VOLUME OF ENTERING TRAFFIC,ADDITIONAL MEASUREMENTS WILL PROBABLY HAVE TO BE CARRIED OUT IN ORDER TO INCREASE THE NUMBER OF CASES OF LOADING FOR THE SIMULATION.THE INTENTION IS TO INPUT MEASURED BANDS OF HEADWAYS INTO THE SIMULATION AND TO RETAIN THEM FOR ALL FORMS OF DESIGN.IN EACH CASE IN ACCORDANCE WITH THE ENTRY CONSIDERED,ONLY THE SPEED OF THE ENTERING VEHICLES IS TO BE VARIED.IF THE MAXIMUM CAPACITY EXPECTED IN RELATION TO THE DESIGN OF THE RAMP IS SUCCESSFULLY DETERMINED,THE ANTICIPATED STUDIES MAY PROVIDE DESIGN AIDS FOR THE USE OF RAMP METERING.