>>Observed that many times in the Chesapeake bridge/tunnel. And in the tunnel there aren't any line changes, it's a stiff white line all the way. It's just that some rookie is driving there for the first time and got shit scared of driving under water. In the summer it may be crawling at 40kmh or less; in the winter, 90-100kmh is the norm. Somehow, this affects both lanes simultaneously.
It's a truism that where there are no on- or off-ramps, traffic flowing slower than the limit has no useful justification and is to the disadvantage of everybody. Yet it's accepted as normal by thousands of commuters. How will everybody feel if it's confirmed that the same handful of commuters reliably provokes it every day? ;-)
Worse is the speed up-slow down waves that can result in nose to tail crashes if a single driver is over- or under-attentive.
Self-driven vehicles may not be perfect, but they should be able to reduce these patterns.
"... They ne'er cared for us
yet: suffer us to famish, and their store-houses
crammed with grain; make edicts for usury, to
support usurers; repeal daily any wholesome act
established against the rich, and provide more
piercing statutes daily, to chain up and restrain
the poor. If the wars eat us not up, they will; and
there's all the love they bear us."
-- Shakespeare: Coriolanus, Act 1, scene 1