We have bike routes all over, and they are signed with something as shown.
But most of these will have a bike lane or sharrows along with the Bike Route signs.
However, I ran into one road that doesn't, it's just signed.
What's the best way to tag these roads? I don't want to cause confusion, but these unpainted (but signed) roads do actually lead to/from better cycling infrastructure, so they should be known.
UPDATE: Thanks for all the input, guys. Having looked into this further, I'm comfortable using the designated tag, at least for this specific road.
My municipality is a bit bipolar with their application of these signs. Most are signed as bike routes with toad markings, but a few are signed only.
Because these "bike routes" connect to more significant cycling infrastructure, I think its more than valid to tag them as “designated” as opposed to "yes" (which would be pretty much every road).
To add even more confusion to the situation, the official Cycling infrastructure map for my municipality seems to not include several areas that have both bike route signs and road markings, so i will ask them if the data is just lagging or if it needs to be updated.
So, unless there's a critical reason why the "designated" tag shouldn't be used in this context, I will leave it at that.
I think it comes down to accuracy, which is what when adding any content to OSM.
Cycle Routes may have different meaning depending on the location. My municipality seems to mark roads that link to cycling infrastructure as cycling routes, even if they aren't part of the cycling network (which are considerably more vast and usually expand across multiple municipalities, provinces, or even the country. I think to use "cycle route" for this specific example isn't accurate.
"bicycle=designated" has been all over the place from examples I've been looking at spanning 100km in either direction. Some mappers seem to only use the "designated" tag on bike paths, while others use them on roads with simple bike lanes. But there's a lack of consistency, so it's hard to know who's right in these situations.
For me, it makes a lot more sense to use the "designated" tag here, instead of "bicycle=yes" (which applies to 99% of the roads here), or the cycle route tag.
At the end of the day, I think most (i.e. non-mappers) are interested in how the data actually works for them. For example, can they see this cycling infrastructure on their bike computer, or does it still appear as a regular road because the tags aren't specific enough? To me, that would be more problematic than a "somewhat accurate" tag. But that's my opinion.