[danaris]

My experience on US highways is that it generally isn't quite that bad: if you're going roughly the speed limit, you will be in company with a significant subset of the commercial vehicles, whose owners mandate following the speed limit (and in some cases enforce it with GPS surveillance).

[sokoloff]

Your description sounds right but also pretty similar to GP’s characterization of a floor at the limit and 10-15 mph higher median with the result that more than half of traffic is passing you at a 20+% speed differential.