VISIBILITY DISTANCES AT ON-GRADE JUNCTIONS

SICHTWEITEN AN PLANGLEICHEN KNOTENPUNKTEN

ACCORDING TO GERMAN SPECIFICATIONS RAL-K-1 69 VISIBILITY TRIANGLES HAVE TO BE KEPT FREE ON AT-GRADE JUNCTIONS TO GUARANTEE APPROACH VISIBILITY. THE DESIGN OF THE SIDES OF THE TRIANGLE BOTH FOR THE MAIN AND THE SECONDARY ROAD IS BASED ON ASSUMPTIONS OF POSITION (DISTANCE FROM THE EDGE OF THE CARRIAGEWAY) AND THE COURSE OF MOVEMENT OF THE PRIORITY AND NON-PRIORITY VEHICLE. BECAUSE OF THE EFFECT OF THESE VALUES ON THE BUILDING UP OF CORNER PIECES OF LAND, THESE ASSUMPTIONS HAVE TO BE TESTED ON ALREADY CONSTRUCTED ENTRY POINTS BY MEANS OF MEASUREMENTS AND OBSERVATIONS, PARTICULARLY SINCE THE DESIGN MODEL IN RAL-K-1 69 HAS ALSO BEEN TAKEN OVER INTO SPECIFICATIONS RAST-E 71 AND RAST-K-1 73. VARIOUS TYPES OF ROAD ARE TO BE DISTINGUISHED IN THE STUDIES. AT JUNCTIONS WITHIN BUILT-UP AREAS AN ATTEMPT IS TO BE MADE TO DETERMINE THE EFFECT OF VEHICLES PARKED WITHIN THE VISIBILITY TRIANGLE ON THE EDGE OF THE CARRIAGEWAY OR ON A PARKING LANE ON ACTUAL VISIBILITY CONDITIONS, AND TO SEE WHETHER THIS TYPE OF PARKING SHOULD OR COULD BE AVOIDED.