This Washington Post article does a great job of parsing out the insane amount of productivity and resources lost through job commutes.
"These 90-minute-one-way workers -- 3.6 million of them -- spend a huge chunk of their lives simply going to and from work. Consider this: If your commute is the typical 26 minutes each direction, that still works out to a total of nine full days a year spent traveling to work and back."
All of those millions of hours sitting in traffic would have a huge impact on the economy if they were stuck back into productive work.
"Consider the transformational effect this would have at the individual level, giving these folks two hours of their day back. And then multiply that two-hour time savings by the 250 work days in a typical year -- that's 500 extra hours a year. Multiply that by 3.6 million workers, and you come out to about 1.8 billion man-hours of potential productivity released back into the economy. That's the time-equivalent of 900,000 full-time jobs."