On my state's main toll road (75 mph speed limit) it is common to be going 90 in the right lane and have most people zip past you like you're standing still. The design of the road only allows one or two places for speed enforcement every 10-15 miles or so.

I've long wondered why the toll authority does not simply do the math on entry and exit and send citations to the top 5-10% of speeders. It's generate many thousands of dollars in revenue for sure.