Why We Want Fewer Roads

Including our largest cities–NYC, LA, and Chicago–roads worth $4.1 trillion in 2016 (the equivalent of $5.4 trillion today) occupy close to one-quarter of the land in U.S. cities.

Perhaps we should consider if we want (and need) all of them.

The Fewer Roads Study

In a new study, scholars estimated that there were 58,000 km² (22,000 mi²) of roadway in 316 U.S. urban areas (PMSAs). They also suggest that we should consider if we want so vast an area to be occupied by roads. As a result, in an article in Journal of the American Planning Association, a University of Pennsylvania professor and two associates cited three kinds of costs. As we would expect, they start with the dollars and conclude that the cost of expanding roads exceeded the benefits by 17%. Next, they cite the externalities that include pollution and traffic fatalities. And then finally, they take us to how the land might have been used.

Expressed in dollars, the authors estimate that, “a 10% reduction in urban roadway from removing, narrowing, or downgrading roadways resulted in an estimated net benefit of $27.8 billion per year.” Through the following table, they provided more detail:

Induced Demand

Last year, we looked at why California canceled its widening plans for I-710. As we explained, California was worried about induced demand. Whenever we expand our roadways, we could induce demand by attracting more cars. Knowing about the expanded roadway, drivers that had been taking an alternate route switch. Similarly, the commuters that were leaving later or earlier revert to their original habits. As a result, transportation experts tell us that a one percent increase in road capacity has resulted in a .9 percent increase in VMT (Vehicle Miles Traveled per person) within five years.

Our Bottom Line: Opportunity Cost

As economists, always we can return to cost remembering that our definition is sacrifice. Next, becoming more precise, we can name the opportunity cost of a decision. Focusing on its most valued alternative, the opportunity cost reminds us that choosing is refusing. For lunch, the opportunity cost of pizza could be a salad. With sleeping later, it could be eating breakfast. And, with urban roads, it is the housing, shops, offices, and restaurants that could occupy that space.

Maybe, rather than taking city streets for granted, we should ponder the alternatives?

My sources and more: Always handy, my Bloomberg CityLab newsletter had the roads story. From there, I visited the source of the Bloomberg article.