The title could also read "just spend more time driving".
I'm only partially kidding. The
average commute in the US is 16 miles and 26 minutes in 1 direction. That means the typical commuter travels 32 miles and spends 52 minutes in their vehicle 5 days per week. That's 45 waking hours per year. Traveling 15% faster would save nearly a full 8hr work day of time. Having just 1 more passenger would double the amount of time saved by traveling faster.
It's all a balance of economy of fuel vs economy of time. Each person will value these considerations differently.
In my case, I tend to drive the speed limit (55-65 in Oregon) when I'm by myself, and go about 6 mph over the limit when I have passengers.
I find that the speed limits in Oregon to be extremely conservative when compared to the limits from other states. CA tends to be 10 mph faster in most driving environments. The Silicon Valley workers time must be more valuable than the barista workers time