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The Sarah Mildred Long Bridge is a lift bridge that carries the US 1 Bypass over the Piscataqua River between Portsmouth, New Hampshire and Kittery, Maine. The bridge is a double deck truss bridge, with the US 1 Bypass road deck above and a railroad bed below. The bridge features two separate movable spans. While the main lift span and its towers are the obvious primary moving feature, the second moving span is only apparent to water and rail traffic. On the north side of the bridge, the first non-trussed section of rail bed lifts up and moves south as a retractable bridge, coming to rest on top of the rail tracks inside the truss. This creates a waterway large enough for most recreational boats to pass through without the need for interruption of automobile traffic on the bridge. Work on a replacement began in January 2015. == History == Completed in 1940, the bridge is the second to carry motor vehicle traffic between Maine and New Hampshire at Portsmouth, and replaced a river crossing dating from 1822.〔(【引用サイトリンク】 title=Summary of ''The Sarah Mildred Long Bridge: A History Of The Maine-New Hampshire Interstate Bridge From Portsmouth, New Hampshire, To Kittery , Maine'' )〕 The bridge was the direct result of the work of the Maine-New Hampshire Interstate Bridge Authority, which had been formed in 1937. The major goal of the bridge project was to relieve congestion in downtown Portsmouth and Kittery, where US 1 crossed the river via the Memorial Bridge, which had opened in 1923. From 1960 until 1972, the bridge, along with the US 1 Bypass north of the Portsmouth Circle, filled a gap in Interstate 95, which had been designated along both the New Hampshire Turnpike and the Maine Turnpike. Although most of the Bypass is four lanes wide, the bridge itself originally had only a three-lane roadbed, with traffic on the center lane switching direction depending on load (the bridge has since been reduced to just two lanes). This, combined with being a drawbridge, placed the bridge far below Interstate highway standards. The turnpikes, and therefore I-95 in the two states, did not directly connect until the opening of the Piscataqua River Bridge and the extensions of I-95 leading to it in the early 1970s. On April 1, 2013, a large tanker ship clipped the bridge, causing "severe structural damage" and leading to the bridge being closed to vehicular traffic.〔(【引用サイトリンク】 title=Sarah Long Bridge sustains 'severe structural damage' in crash, DOT says; Bridge closed to vehicular traffic after incident )〕 The I-95 Piscataqua River Bridge was the only Portsmouth bridge over the Piscataqua remaining open. The bridge was repaired and re-opened to vehicle traffic on May 13, 2013.〔http://www.seacoastonline.com/article/20130514/News/305140422〕 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「Sarah Mildred Long Bridge」の詳細全文を読む スポンサード リンク
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