This is not merely a story of the sins of an other. The U.S. Interstate Highway System—perhaps the greatest road widening project in human history—was sold in large part not as a transportation project but as a military project, a project both for national defense and ensuring internal order. New federal highways granted easy access for tanks and military equipment to America’s urban cores, which would be put to regular use in the political disturbances to come. A new, state-sanctioned mode of living would be enshrined, both in where the roads went and in where they didn’t, with strict separation of transportation modes, limited access, and massive elevated structures. And of course, in all this, the costs of this program fell hardest on America’s poor and minority neighborhoods.

In all cases, wide, straight, legible streets serve the interests of those in power. They allow for the easy mobilization of conventional forces and easier state management of society. And in too many cases, street widening and straightening projects have been used to dispossess and displace smallholders and marginal groups—small businesses, the poor, and racial and political minorities. In their place, wide streets are frequently designed to aesthetically impose a hegemonic vision of the good urban life. The narrow, winding streets that characterize virtually all human cities laid out before the Enlightenment—with notable exceptions in history’s worst authoritarian states—work against each of these. They create spaces that small groups of poorly armed people can defend. By efficiently using urban land, they create space for all comers. And with their unplanned storefronts and winding tendencies, they prevent the imposition of any single ideological vision on cities.

There are more than enough utilitarian cases for fighting road widenings and new urban freeways. And in the stodgy halls and meeting rooms in which public policy gets made, they may be more than enough. But we are selling our case short if we fail to make the case for how urban design can uphold or undermine a liberal society. A free country, as with a free city, depends on the wide distribution of power across various individuals and institutions. In practice, distributed power means the right to self-defense and strong protections for property rights, whatever the plans of the rich and powerful may be. Letting narrow streets be fulfills both of those objectives. Our liberal urban society is strengthened in a subtle way by narrow streets. They create a visual order that denies one ideology or religion primacy (in contrast to the monumental role of a cathedral or government building at the head of a broad boulevard). They privilege local knowledge and thwart systematic controls. They create a shared space that forces different road users to commingle and compromise. Thus, street width isn’t merely a “technical” problem to be resolved by experts. It’s a problem that goes to the very heart of the question: What kind of society do we want?