The Contribution to the Procedure of Capacity Determination at Unsignalized Priority-controlled Intersections

The problem of minor vehicles crossing or merging into themajor stream at unsignalized priority-controlled intersections iswell-known. Numerous solutions involve various assumptionsconcerning the major headway distributions, number of majorlanes, critical gap distributions, etc. Such cases can be dividedinto two main groups: intersections with two streams (one majorand one minor stream) and intersections with more thantwo streams (more than one major stream and one minorstream). At roundabouts, also at single-lane roundabouts,there are similar problems like the ones at other unsignalizedpriority-controlled intersections. A vehicle at the roundaboutapproach can only cross the pedestrian crossing when a sufficienttime-gap between two pedestrians (or cyclists) is provided.A vehicle at the roundabout entries can only merge into the majorstream when a sufficient gap between the two vehicles in themajor stream is provided. Because of that, single-lane roundaboutscan also be treated as unsignalized intersections withtwo major lanes: the first one in its circulatory roadway and thesecond one on the pedestrian crossing.