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A seagull intersection〔John Harper, Wal Smart, Michael de Roos: (''Seagull Intersection Layout. Island Point Road – A Case Study'' ) 2000 – 2010〕 or continuous green T-intersection〔Federal Highway Administration: (''Alternative Intersections/Interchanges: Informational Report (AIIR)'' ), Publication Number: ''FHWA-HRT-09-060'', April 2010〕 (also known as a turbo-T〔 (in Florida) or High-T intersection (in Nevada and Utah)〔Utah DOT: http://www.udot.utah.gov/5400south/〕〔Nevada DOT: (''US93 Lakeshore v4 Handouts'' )〕) is a type of three-way road intersection, usually used on high traffic volume roads and dual carriageways. This form of intersection is popular in Australia and New Zealand, and sometimes used in the United States and other countries. == Design == Seagull intersections get their name from the pattern that the two right-turn lanes make when looking down from the air. In a seagull intersection, one or more lanes of traffic on the arterial road, on the carriageway opposite the intersecting side road, are free flowing, that is, one direction of traffic on the arterial is allowed to travel straight through without stopping. The free-flowing lane(s) are called "continuous green through lane(s)" (CGTL). For the free-flowing through lanes, access into and out of the side road is provided via turn lanes separated from the through lanes in a configuration similar to exit and entrance ramps at an interchange; however, the turn lanes are at the same grade as both carriageways of the arterial and are located on the same side as the oncoming traffic. Those wishing to turn right into the side road at the intersection, bear right into the turn lane, which forms one "wing" of the seagull. Here, they meet the opposite carriageway and the side road. Traffic wishing to turn right out of the side road, cross the intersecting carriageway, drive up the other "wing" of the seagull, and merge onto the other carriageway.〔(''Intersection Decision Guide'' ), Indiana Department of Transportation, Version 1.1 published 14 January 2014, retrieved 25 August 2015, P. 44〕 For the arterial carriageway adjacent to the side road, access into and out of the side road is ordinarily handled like a conventional T intersection. However, some seagull intersections may have a second, smaller "seagull" formed by two left turning lanes into and out of the side road. Different methods are used to control traffic where two right-turning movements and the through movement meet. Most intersections use traffic lights, while others use give way (yield) and stop signs, and sometimes roundabouts. This design type has been proven to provide sustainable benefits when compared the traditional T-intersection design. By reducing delay through the intersection, automobiles use less fuel on average passing through the intersection, and thus emissions are reduced across the intersection. The savings per vehicle may not seem very significant, but when scaled to account for all automobiles passing through the intersection, the total emission savings are significant. Additionally, there are economic and social benefits to reducing delay time and allowing drivers to pass through the intersection quicker. In the Netherlands, this type of intersection occurs by default when a T-junction has a bicycle path on the continuing road, and is not intersected by a roadway for motorized vehicles. The bicycle path may ignore red lights; it is only turning cyclists that must wait for the red light.〔(''Cycling past red lights in the Netherlands'' ), YouTube, published 24 October 2012〕 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Seagull intersection」の詳細全文を読む スポンサード リンク
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