How to distinguish ทํางพิเศษ (expressway)?

In Thailand, there are…

ทํางพิเศษ (expressway), managed by Expressway Authority of Thailand (EXAT)

and there are other controlled-access highways, managed by the Department of Highway (DOH)

Both are tagged with

highway=motorway

, but for they differ amongst other things in that

  1. different access restrictions apply (e.g. no motorcycles allowed on expressways)

  2. different default speed limits apply (when nothing else is signed)

  3. different route emblems should be shown (in the UI of navigation applications)

Question: How can these two types of motorways be distinguished by OpenStreetMap tags? Is there any tagging in place that already makes this distinction? If not, do expressways have ref codes? (Because if they don’t, then at least they can be told apart by looking at whether or not a motorway has a ref or not)

Expressway do not have ref codes. We can use it to distinguish them from motorway.

Thank you!

This got me thinking, should we add operator=exat or similar to the expressways?

There is also expressway=yes, but it is mostly used in the United States, where expressways have a different meaning than in Thailand: In the US, freeways are motorways and expressways are usually very similar to trunk / motorroad. While in Thailand, expressways seem to be rather toll+super-freeways.

operator=exat is fine, it may not be technically correct because some expressways are concessions to private companies such as BEM. Anyway, it’s possibly the best tag we have.

(nevermind, post deleted)