[ZeroGravitas]

The (bad) justification for overtaking seems a much better justification for the slower truck to fix their calibration and go faster.

Lots of good info but it all feels a bit like it is being used to create a "just so story" to support whatever the current status quo is.

[schiffern]

Right. If 0.5 mph is so valuable (which I believe), how do we explain the slow trucks? How do we fix the slow trucks?

[ben_w]

IIRC, the difference in radius between fresh tires and those worn down to just before they need replacing, changes the actual speed at any given speedometer reading by about 2%.

C=πD and all that.