Most commonly you find them down very old, narrow, country lanes, where there simply isn’t space for true segregation. But equally, there’s usually no need to use these roads a cyclist, as there are normally more direct dedicated cycle routes. You frequently only use them because your specifically looking for a scenic route, or something a little unusual to cycle down.
In other parts of the world, they will also have their place in space constraint locations, or in large networks of small country lanes, where providing segregated infrastructure simply isn’t possible or viable due to lack of space, or extremely low volumes of traffic.
I personally think the UK could benefit substantially from these types of roads, if country lanes where converted. The lanes are barely big enough for bi-directional motor traffic, and occasionally not even that wide. Providing edge lane roads would encourage motor traffic to remain in the centre of the road, where they’re substantially less likely to collide with cycle or pedestrian traffic, which may be hidden around one of the many blind corners.
It's not better than a properly separated bike path, but it is better than a painted bicycle gutter that motorists are comfortable driving 50mph inches from.
Except given American drivers insistence on their own primacy and infallibility on the road, I can’t envision an edge lane working.
The main road closest to my house was recently (3 years ago) re-striped from two lanes each direction to 1 lane + bike lane. Car frequently ignore the bike markings and simply use the bike lane for aggressive passing of vehicles going the speed limit. I damn near got run down from behind by a bro-dozer making one of these aggressive moves in the bike lane.
Too many American drivers are self-entitled wankers, and suburban roads are too wide and too fast, for this to work. (Of course, wide road, no reason for this model, but I suspect American drivers simply wouldn’t tolerate this design)
Unless I've fundamentally misunderstood the concept.
But, when comparing paint with paint, this will slow drivers down more than the standard divided two car lane two way road they are accustomed to, due to the single center motorized lane that you pointed out.
As a commenter from the Netherlands pointed out somewhere else on this post, this paint only approach is supposed to just be one cost effective tool for very low throughout roads, the lower end of a panoply of system-level methods to design separation between ped, cycle, and car velocities, part of a system that first prioritizes proper cycleways over paint-only methods.
Unfortunately in North America we really have to crawl before we can walk on this one.
But, like you, I have questions about how this configuration would work (in the US, in my case). I can see it working well in towns and suburban roads in some European nations - I’m thinking Scotland here - where default speeds are lower, roads are already shared with parking (so single-tracking is a known procedure), and drivers generally aren’t assholes.
In the US, most suburban streets are posted at 25-40mph, and actual speeds tend to be higher yet, which seems WAY too fast for edge lane roads or any other mixed use roadway. Heck, in my area, we have dedicated (but not protected) bike lanes and on some roads, they’re downright scary because the traffic 3’ away is going 50mph.
the important bit is segregating traffic by inertia and mass. i'd personally love to see all the car/truck thoroughfares (roads) put underground, with people getting explicit priority on the above-ground, mixed-use streets.
One of these roads is two blocks away from me. I’m going to go have a look at it later today, but the road it’s on is very similar to the road I live on: two direction street, residential parking on both sides, not four car widths’ wide, so people are already “taking turns” and used to it.
I bet it works exactly like the street I live on, only using more paint.
I think it's a little naive to imagine it would work in north america. drivers here need more than a gentle reminder to not run other users off the road.