If Monderman’s ideas seem heretical to many in the United States, it’s worth considering exactly who created the American system in the first place, and why. In Fighting Traffic, a fascinating history published earlier this year, Peter D. Norton documents how the automobile industry, in concert with ­self-­proclaimed traffic experts, helped shift the debate on urban traffic safety during the 1920s. As motorization levels soared, measures such as “speed governors” on engines, a once popular idea, fell out of favor, and the urban street was redefined from a place with various uses to a channel for moving the most vehicular traffic as quickly as ­possible.