92 Take a Ride on the Interstate

The United States has one of the best highway systems in the world. Interstates connect just about every large and mid-sized city in the country. Did you ever wonder why such a complete system of excellent roads exists?

For an answer, you would have to go back to the early 1920s. In those years just after World War I, military men wanted to build an American highway system for national defense. Such a system could, if necessary, move troops quickly from one area to another. It could also get people out of cities in danger of being bombed. So-called roads of national importance were designated, but they were mostly small country roads. In 1944, Congress passed a bill to upgrade the system but did not fund the plan right away.

In the 1950s, the plan began to become a reality. Over $25 billion was allocated, and construction began on about 40,000 miles of new roads. The idea was to connect the new system to existing expressways and turnpikes, such as the Merritt Parkway in Connecticut and the Pennsylvania Turnpike. And though the system was built mostly to make car travel easier, defense was not forgotten. For instance, highway overpasses had to be high enough to allow trailers carrying military missiles to pass under them.

By 1974, the system was mostly completed. (A few additional roads would come later.) Quick and easy travel between all parts of the country was now possible.

92 畅游州际公路

美国拥有世界上最完善的公路系统之一。州际公路连接着全国几乎所有的大型和中型城市。你有没有想过，为什么会有这样一套完备的优质道路系统？

要找到答案，得回到20世纪20年代初。第一次世界大战刚结束的那几年，军人希望建立一套美国公路系统，用于国防。必要时，这套系统可以快速将军队从一个地区转移到另一个地区，还能让人们撤离有被炸危险的城市。当时指定了所谓的“国家重要道路”，但它们大多是小型乡村道路。1944年，国会通过了一项升级该系统的法案，但并没有立即为该计划提供资金。

20世纪50年代，这项计划开始成为现实。政府拨款超过250亿美元，开始修建约40000英里的新道路。计划是将新系统与现有的高速公路和收费公路连接起来，比如康涅狄格州的梅里特公园大道和宾夕法尼亚州收费公路。尽管这套系统主要是为了方便汽车出行而建，但国防需求也没有被遗忘。例如，公路立交桥必须足够高，以允许装载军用导弹的拖车从下方通过。

到1974年，该系统基本完工（后来又增加了几条道路）。如今，在全国各地区之间快速便捷地通行已成为可能。