Think now of the US interstate highway system. Like the internet that followed, the highway system was the subject of much hype and conjecture. Most notably, Norman Bel Geddes’ -designed General Motors Futurama exhibit at the 1939 New York Word’s Fair. In it we saw magical highways connecting our cities, and whisking motorists from New York to LA in 24 hours. He predicted cities would expand their commuting radius by 600% by 1960. The seven acres of exhibits dazzled. The attending crowds, who mostly took trains from hot, huddled apartments, fell in love with the dream.

The Federal-Aid Highway Act of 1956, signed into law by President Eisenhower on June 29, codified Bel Geddes’ vision, and set in motion the enormous machinery necessary to build it.

And strangely, as it all began to take shape, it all looked pretty much as Bel Geddes had shown us in 1939 and earlier. Even so, it was the late 1960s before we started to understand the social change it brought with it. A 1970 study showed that home prices increased $65 for each minute closer (by highway) to the central business district they were, and that churches closest to highways grew far faster than those further from them. These were seen as positive trends, it was only later that we recognized urban flight, or the many other facts of a highway-enabled culture.

Change can be hard to see, to understand, and especially hard to judge, even in retrospect. More importantly, the lesson here is that by the time we see a change, it’s already happened.

(Highway history details from Tom Lewis’ Divided Highways.)