INVESTIGATION INTO THE TRAFFIC FLOW ON ENTRANCE RAMP TERMINAL AREAS AT GRADE-SEPARATED JUNCTIONS WITH LANE REDUCTION

UNTERSUCHUNG DES VERKEHRSABLAUFES IM ENDBEREICH VON VERBINDUNGSRAMPEN PLANFREIER KNOTENPUNKTE BEI VERENGUNG VON EINEM ZWEISPURIGEN AUF EINEN DRESPURIGEN QUERSCHNITT

The traffic flow on ramp terminal areas with lane reduction from two lanes to one lane is examined. Traffic flow is assessed with respect to safety and capacity. On the basis of the knowledge obtained, the most appropriate type of the dual-lane/single-lane transition and the most appropriate marking or signposting of hte transition zone itself is determined. After preliminary investigations into the geometric design of lane reduction areas, eight different designs were tested under realistic conditions on a representative test section. The design elements were barrier line, gore, no passing, and pavement width transition sign. The traffic characteristics used were weaving, speeds, headways, platoons, overtaking or passing, and driving over gores. The results show that lane reductions from two lanes to one lane at ramp terminals do not pose problems if traffic volumes do not exceed the specifications of the corresponding guidelines. On the basis of the traffic flow changes measured, no detrimental effects were to be expected on both safety and capacity. The relative smoothness of traffic flow was brought about by means of a clearly visible gore and appropriate advance warning signs placed on both sides of the pavement. Additional measurements to improve the meningfulness of the results and for their confirmation were carried out on three test locations designed and equipped according to this principle. The findings were directly included in the specifications of the RAL-K-2(1976-(Guidelines for the design and alinement of highways outside built-up areas, junctions). /Author/

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    Bundesminister fuer Verkehr

    ABT. Strassenbau, Lennestrasse 30
    D-5300 Bonn,   Germany 
  • Publication Date: 1977

Language

  • German

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Filing Info

  • Accession Number: 00178419
  • Record Type: Publication
  • Report/Paper Numbers: Report No. 235 Monog Ser.
  • Files: TRIS
  • Created Date: Jul 29 1978 12:00AM