Geometric Design of Suburban Roundabouts

Professional paper - Professional paper

• Author: Saša Ahac
• Author: Vesna Dragčević
• Author's institution: University of Zagreb; Faculty of Civil Engineering; (Transportation Engineering)
• Scientific / art field, discipline and subdiscipline: TECHNICAL SCIENCES; Civil Engineering; Transportation

Abstract (english)

A modern roundabout is an intersection with a circulatory roadway at which the vehicle speed is low, and the traffic is continuous and circulating in one direction around the central island towards the exits at the approach legs. Modern roundabout design is an iterative process that is composed of the following steps: (1) the identification of the roundabout as the optimal traffic solution ; (2) the definition of the number of lanes at the intersection based on the required capacity and the level of service ; (3) the initial design of the roundabout geometry ; (4) design vehicle swept path, the fastest path analysis, and visibility performance checks ; and (5) detailed roundabout design if the results of the performance checks are in line with the design recommendations. Initial roundabout geometry design elements are not independent of each other ; therefore, care must be taken to provide compatibility between them. An overview and a comparative analysis of the initial geometric design elements for suburban single-lane roundabouts defined in roundabout design guidelines and norms used in Croatia, Austria, France, the Netherlands, Germany, Serbia, and Switzerland is given in this entry.

• Keywords (english): approach alignment; outer radius; circulatory roadway; apron; splitter island; roundabout entry; roundabout exit; longitudinal slope
• Language: english
• Publication type: Professional paper - Professional paper
• Publication status: Published
• Peer review: Peer review - international
• Publication version: Published version
• Journal title: Encyclopedia
• Numbering: vol. 1, no. 3, pp. 720-743
• p-ISSN: 2673-8392
• DOI: https://doi.org/10.3390/encyclopedia1030056
• URN:NBN: urn:nbn:hr:237:308717
• Publication: 2021-08-05
• Document URL: https://www.mdpi.com/2673-8392/1/3/56
• Type of resource: Text
• Access conditions: Open access
• Created on: 2024-07-11 06:02:16