42小时，除以365天，每天在路上6.9分钟。与直觉不符。

查了一下Texa Transportation Institute网站：

https://tti.tamu.edu/2015/08/26/traffic-gridlock-sets-new-records-for-traveler-misery/

其中说：

According to the 2015 Urban Mobility Scorecard,
travel delays due to traffic congestion caused drivers to waste more
than 3 billion gallons of fuel and kept travelers stuck in their cars
for nearly 7 billion extra hours – 42 hours per rush-hour commuter.

每个rush-hour commuter每年多花42小时，平均每天6.9分钟，每个工作日多花10分钟。差不多。

再以70亿小时，除以42小时，得出约1.6亿人，commuter人数？