One of my favorite roads in Washington State is Highway 2. On this road, we have the periodic passing lane, at least when we're going Eastbound, we do. Westbound has fewer of those passing lanes; though, I think the lane in the Eastbound side is dashed, so you can actually pass using it if there's not much traffic going Eastbound. Nevertheless, when stuck behind someone who is clearly not following the "more than 5 people behind you: pull over" rule, I long desperately for the passing lane to come, as it appears all the time for the Eastbounders.
I have seen exactly the problem you're describing on /several/ occasions; but, I wouldn't give up the double-lane road, because sometimes people do stay their previous speed and you /can/ pass them. This road is a mountain pass, and so there are several curvy sections, all of which are too dangerous to pass in because you can't see far enough to confirm no cars are coming. When the road grows to 2 + 1 again, you'll see several people enthusiastically pass the slow person and from their slower speeds.
tl;dr: live in the US, love the 2+1 lane when it's around.
"It turned out that not only did safety improve, but it was also easier to overtake than before as the 2-lane sections provide safe overtaking opportunities."
"After some good experiences with test roads the system has been used often in places where the amount of traffic does not justify construction of a dual carriageway expressway but remote rural areas should be connected to major towns with a high speed road."