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rica. Longspan, segmentedconcrete, cablestayed bridges such as Hale Boggs in Louisiana and the Sunshine Skyway in Florida, and remarkable tunnels 12 like Fort MC Henry in Maryland and Mr. Baker in Washington developed under the nation39。 ” 8 外文翻譯 Highways Early in the 20th century, most of the streets and roads in the . were made of dirt, brick, and cedar wood blocks. Built for horse, carriage, and foot traffic, they were usually poorly cared for and too narrow to acmodate automobiles. With the increase in auto production, private turnpike panies under local authorities began to spring up, and by 1921 there were 387,000 miles of paved roads. Many were built using specifications of 19th century Scottish engineers Thomas Telford and John Macadam (for whom the macadam surface is named), whose specifications stressed the importance of adequate drainage. Beyond that, there 9 were no national standards for size, weight restrictions, or mercial signs. During World War I, roads throughout the country were nearly destroyed by the weight of trucks. When General Eisenhower returned from Germany in 1919, after serving in the . Army39。在 開(kāi)始修建的那一年 ,艾森豪威爾 將軍 曾說(shuō): “ 通 7 信 系統(tǒng) 和交通 運(yùn)輸 系統(tǒng) 聯(lián)合起來(lái)的巨大 力量 正 是 我們國(guó)家 最重要的活力來(lái)源。 到上世紀(jì)末,美國(guó)已經(jīng)建成了集公路、住宅區(qū)街道、高速公路 以及免費(fèi)高速公路 于一體的巨大的 道路網(wǎng)絡(luò),為數(shù)以百萬(wàn)計(jì)的機(jī)動(dòng)車輛提供了便利 。 公路系統(tǒng)并不僅僅是通過(guò)提供運(yùn)輸線路來(lái)影響美國(guó)的經(jīng)濟(jì),它還促使了很多附屬產(chǎn)業(yè)的產(chǎn)生和發(fā)展,比如說(shuō)服務(wù)站、汽車旅館、飯館以及購(gòu)物中心。但最重要的是,這個(gè)州際系統(tǒng)給人們提供了 他們最珍惜的東西:個(gè)人出行快捷方便。高速公路上的事故死亡率僅為美國(guó)其他道路的一半(高速公路旅客周轉(zhuǎn)量 1億人英里的死亡率是 ,而其他公路旅客周轉(zhuǎn)量 1 億人英里的死亡率則是 )。 今天 ,州際交通體系不僅連接了美國(guó)國(guó)內(nèi)的各大 主要 城市,并且把美國(guó)與加拿大和墨西哥連接了起來(lái)。過(guò)去是以生產(chǎn)推動(dòng)銷售,物流模式的特點(diǎn)是高庫(kù)存;而現(xiàn)代企業(yè)生產(chǎn)方式則是市場(chǎng)需求拉動(dòng)生產(chǎn),相應(yīng)的物流模式也由高 效率、低成本的 運(yùn)輸系統(tǒng) 和信息系統(tǒng)替代高庫(kù)存。由州際公路項(xiàng)目所發(fā)展起來(lái)的交通控制 系統(tǒng) 和 建筑方案 ,很快就影響了全世界的 高速 公路建設(shè),并在改善城市 市區(qū) 街 道狀況 和交通模式方面起到了不可估量的