On the transportation side, I look at our history of investing in infrastructure.
We spent (and are spending) billions and billions of dollars creating the interstate-highway system, and increasing the size of our airports and ports.
There is this default assumption that we are going to keep growing those things bigger and bigger, off into whatever kind of future we imagine. I protest that sort of assumption—that everything we are doing is about getting bigger and bigger.
Ultimately, sustainability means coming to terms with natural biophysical limits.
So we have to get past this idea of planning around extrapolation of past trends.
That the future may be different than the past is the first thing that we need to come to terms with. This is where the idea of peak roads comes in: If we can say to ourselves, “We have as much road capacity today as we will ever need,” then we can start to ask what that means in terms of how we should actually start designing our cities.
This shouldn’t be thought of as a default “anti-roads” statement. But our numerical models show that we simply may not have enough fuel (and biofuel, and electric cars) to use more road capacity than what we have today.
If we can start to grapple with the fact that we can actually get better instead of getting bigger, then we have started on the path towards sustainability. And I think until we can really wrap our heads around that we are fighting an uphill battle.