EVALUATION OF VARIOUS CONDITIONS OF TRAFFIC FLOW BY LEVEL OF SERVICE

BEURTEILUNG VERSCHIEDENER ZUSTANDSFORMEN DES VERKEHRSFLUS SES DURCH LEVEL OF SERVICE

THE WORK BEGAN WITH A STUDY OF METHODS OF OBTAINING PARAMETERS AND CHARACTERISTIC VALUES WHICH DESCRIBE THE QUALITY OF TRAFFIC. CRITERIA FOR ESTABLISHING AND LIMITING SECTIONS OF ROAD FOR MEASUREMENT WERE DRAWN UP. OF THE GEOMETRIC VALUES OF A SECTION OF ROAD, THE EXTENT AND LENGTH OF THE GRADIENT WILL PROBABLY HAVE THE MOST NOTABLE INFLUENCE ON THE QUALITY OF TRAFFIC FLOW. BECAUSE OF THIS SECTIONS OF ROAD ON WHICH MEASUREMENTS WERE TO BE CARRIED OUT WERE DIVIDED INTO THE CATEGORIES FLAT, HILLY AND MOUNTAINOUS. BECAUSE OF THE COMPARISONS WHICH WILL HAVE TO BE MADE LATER, THE SELECTED SECTIONS OF ROAD HAVE TO MEET THE FOLLOWING CONDITIONS: (1) NORMAL CROSS-SECTION WITH TWO LANES AND A PARKING LANE; (2) AS REGARDS TRAFFIC LOADING, UNIFORM TRAFFIC STRUCTURE OVER THE WHOLE SECTION AND SUFFICIENTLY HIGH DAILY TRAFFIC VOLUME IN ORDER TO OBTAIN THE LIMIT VALUES OF THE CAPACITY OF A ROAD; (3) THE LENGTH OF THE SECTION HAD TO BE 20-25 KM, IN ORDER TO LIMIT THE EFFECT OF CHANCE EVENTS ON TRAFFIC FLOW. MEASUREMENTS WERE BEGUN IN JUNE 1975. THE AIM WAS TO DETERMINE THE EXTENT TO WHICH DESIRED SPEED COULD BE ATTAINED IN RELATION TO TRAFFIC DENSITY, TRAFFIC COMPOSITION AND HIGHWAY GEOMETRY.