No kidding, the American Trucking Association wants trucks to go slower:

The plan calls for governors on new trucks to limit speeds to no more than 68 mph, a call to reduce the national speed limit to 65 mph for all vehicles…

The proposal isn’t just altruism. It’s another instance in which self-interest and the public interest are aligned. Soaring diesel prices make it economical to reduce speed, thereby saving fuel and carbon emissions.

We’ve heard anecdotes about this, and we even seen some empirical research. Now we’re seeing intentional policy. There’s other good stuff in the plan too:

Also on the list is reducing engine idling, improving highways, using more productive truck combinations, and setting fuel economy standards for trucks.

Apparently, a number of trucking companies are already taking the initiative to get creative about reducing fuel use. They’re crunching the numbers to find savings — and then they’re reducing load weights, switching to effiicient tires, upgrading lubricants, and installing aerodynamic panels.

Chalk this up as more evidence that the transportation sector really does respond to price signals. Just as in other energy sectors, smart policies can wring all kinds of efficiencies out of the transportation system.