Comment by davidwhodge

Alrighty here's the first graph. Note that this is average speed, so any trips with an average speed near the right by definition have some parts of the trip faster than the average, so the actual drop at 80 mph isn't quite as severe as it looks.

https://imgur.com/a/c10NXaz

the reason for the cutoff is that because it's pretty hard to have a trip with an AVERAGE speed above 80mpg. It's very rare in my large dataset.