I don't know how they got those numbers either, although I could speculate on a simple way to do a back-of-envelope calculation by Multiplying the following: *

I don't know how they got those numbers either, although I could speculate on a simple way to do a back-of-envelope calculation by Multiplying the following: * commuter average hourly wage * time spent in traffic (basically time the commute took in traffic minus the amount of time the commute would hypothetically take if drove at the speed limit) That's easy although imperfect...might also want to account for other things like delayed meetings due to traffic.