What makes a motorway?

A few months ago MapAnalyser465 changed West Kanchanaphisek Road (as well as some others) to highway=motorway, giving the edit summary, “Updated Kanchanaphisek Road (West) to Motorway Standard from Trunk Road Standard due to Grade Separation.” Now this is clearly incorrect, since although the entirety of Bangkok’s outer ring road is supposed to be a motorway, the western section has never been upgraded to feature complete access control. I’ve left a changeset comment, and am going to revert the change. However…

One of the roads MapAnalyser465 also tagged as motorway is the Borommaratchachonnani Elevated Highway. Now despite the fact that it’s ten metres up in the sky and motorcycles aren’t allowed up there, I’ve never really thought of it as a motorway/expressway/etc. It’s road standards aren’t quite that high—a few years ago it was repainted with three narrow lanes and no hard shoulder—and motorcycles can quite easily illegally go up there without having to break through a single barrier (since it’s toll-free). It also belongs to neither the EXAT’s expressway or DOH’s motorway system, and frankly, nobody I know calls it a motorway. It’s also an island that doesn’t connect to any of the motorway/expressway systems.

However, it’s not the only elevated road that’s not part of the formal motorway/expressway system. Don Mueang Tollway isn’t either, its northernmost section is also toll-free, and it’s not unheard of that motorcyclists sometimes illegally use it. This gave me pause about reverting Borommaratchachonnani to highway=trunk, since it would seem to introduce a discrepancy in the tagging scheme.

What do you think? I still think it should be trunk, but would like to hear of others’ opinions before continuing.

PS Another dilemma is the Bhumibol Bridge. It’s not part of the expressway, but motorcycles aren’t allowed up there, and it’s not terribly clear where the expressway ends and normal highway begins anyway. It doesn’t seem unreasonable to tag it as highway=motorway, given its characteristics, though I would still prefer not to.

What about the “motorroad” tag? The fact that traffic law enforcement isn’t really strict in Thailand is something different…

Thanks. I hadn’t known of that tag before.