New Type of Roundabout: Roundabout with “Depressed” Lanes for Right Turning – “Flower Roundabout”

Abstract

Recently, many of the foreign traffic-safety analyses point out the low level of traffic safety in multi-lane roundabouts. This problem is resolved in several ways in different countries; however, the solution, whereby the number of conflict points is diminished (e.g. turbo roundabout) has proven to be the most successful. However, the turbo roundabout also has its deficiencies: it has conflict crossing points and larger reconstruction of the existing two-lane roundabout is needed when the turbo roundabout is to be implemented instead of the existing one. In the paper a new type of roundabout has been introduced; the roundabout with “depressed” lanes for right turning (“the flower-roundabout”). Financially speaking, the main advantage of the new type of roundabout is that it can be implemented within the dimensions of the already existing “normal” two-lane roundabout. From the traffic-safety point of view, the main advantage of the new type of roundabout is that it has no crossing conflict points. KEYWORDS: traffic safety, roundabout, turbo roundabout, roundabout with “depressed” lanes for right turn