Issues in the Planning and Management of Roundabouts in Cold, Snowy Regions: Traffic capacity reduction at a roundabout with a compacted-snow road surface, and truck apron design that considers snow removal
Two-thirds of Japan is classified as cold and snowy. When roundabouts are planned and managed, snow must be considered. In this study, first the reduction in traffic capacity was determined for a roundabout with a snow-covered surface on a test track. Vehicle gap parameters were measured at a roundabout. These parameters were critical gap time (tc), follow-up time (tf) and minimum headway time for vehicles on the roundabout’s circulatory roadway (ɾ). When the roundabout had a compacted-snow surface, the entry capacity was about 300 vehicles/hour less than when it had a dry surface. However, when the surface was compacted snow spread with non-slip abrasives, the entry capacity was reduced by only about 150 vehicles/hour from that for the dry road surface. Next, tests were conducted on damage to the truck apron structure from snow removal operations. Three types of apron with various height and angle conditions were tested in terms of damage to the apron from contact by snow removal machinery. The types were four conventional stepped aprons, one step-and-gradient apron, and four gradient aprons (i.e., a total of nine aprons). The tested snow removal vehicles were a wheel loader and a motor grader. The gradient aprons were found to be damaged less than the other types of aprons. This paper discusses issues to be addressed in the planning and operation of roundabouts in cold, snowy regions, specifically their decreased flow rate when covered with compacted snow and designs for their aprons that resist damage from snow removal machinery.
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Supplemental Notes:
- This paper was sponsored by TRB committee ANB75 Standing Committee on Roundabouts.
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Corporate Authors:
500 Fifth Street, NW
Washington, DC United States 20001 -
Authors:
- Munehiro, Kazunori
- Takada, Tetsuya
- Sato, Shingo
- Takamoto, Satoshi
- Ishida, Tateki
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Conference:
- Transportation Research Board 96th Annual Meeting
- Location: Washington DC, United States
- Date: 2017-1-8 to 2017-1-12
- Date: 2017
Language
- English
Media Info
- Media Type: Digital/other
- Features: Figures; Photos; References; Tables;
- Pagination: 22p
- Monograph Title: TRB 96th Annual Meeting Compendium of Papers
Subject/Index Terms
- TRT Terms: Design capacity; Frigid regions; Roundabouts; Snow; Snow removal; Snowplows; Traffic characteristics; Traffic flow
- Geographic Terms: Japan
- Subject Areas: Design; Highways; Maintenance and Preservation;
Filing Info
- Accession Number: 01626608
- Record Type: Publication
- Report/Paper Numbers: 17-00960
- Files: PRP, TRIS, TRB, ATRI
- Created Date: Feb 27 2017 9:25AM