It will never happen in my lifetime, Not jus roads here where I live there is no pavements so you are in the road, as for hotels, and other accommodation also villas there would have to be major alterations to door ways and bathrooms, simple things like taking a shower or a bath and the property all being on one level, none of these stupid little steps everywhere, Not a chance.
Last couple of weeks I have had my family here with a little one it was bad enough with a buggy.
We went to a few restaurants and there you notice how difficult it would be with a wheel chair, one place we went to the ramp was so steep it was easier to carry the buggy up the steps as for the toilet forget it, it's up the side of the hill but at least they had a handrail.
There is no industry standards and regulations here, as for fire regulations how would you be able to evacuate in a wheelchair, We have an apartment and one glaring problem is the fire doors open in, that's just a start with.
I did read an article a while ago and catering for people with disabilities in the hospitality industry is huge, not happening in Thailand.