However, I am not sure the analysis method used in this article is really the way to look at this issue. The fact that lots of people spend 15 minutes sitting on their rear is not a serious problem, despite the fact that you can multiply that 15 minutes by millions of people to get a large number.
The problem is that some people have very long commutes. 30 minutes or more is a problem. An hour or more is a serious problem. 90 minutes or more is, for most jobs, ridiculous.
Actually, I see rather more good news than bad news in the referenced statistics. According to the source ([1], see the table on page 2) only 2.3% of Americans have a one-way commute of 90 or more minutes. Only 7.5% have an hour or more. But 33.5% -- more than a third -- have 30 minutes or more; that is troubling.
By the way, the statistics in the source[1] strike me as a little suspect. In particular, the big bump at "30 to 34 minutes" suggests that a lot of people were thinking, "Oh, about 30 minutes." That kind of estimation is not mentioned among the possible sources of error. Someone was not thinking clearly enough when that Census Bureau report was written.