Zzzz read my posts carefully, I haven't said I can tell by looking - I can't, but people's behaviour, body language and the crass excuses that come out of their mouths give me all the ammunition I need.
Some of the comments here are unbelievable and show staggering ignorance.
Large cubicles in the ladies and gents toilets which normally have a sink in them = designed for disabled people to use, large enough to have an assistant with you, big enough to get a small buggy into, perfectly set up to change a stoma bag, use a catheter or empty a catheter bag if you aren't in a wheelchair.
Accessible toilets, the ones with the wheelchair symbol on the door = designed to be accessible for people in a wheelchair, with or without an assistant. Sometimes these toilets have a baby changing facility in them too, at a height that makes them useless to a parent in a wheelchair
Sometimes accessible toilets have a radar lock, I repeat Anyone can buy a radar key on eBay, Amazon, keycutters, some pharmacies, any shop that sells disability equipment for a couple of quid. Alternatively you can call into your local council office with proof of your disability and get one for a fiver after filling in the three page form.
Toilets marked as changing places, nearly always with a radar lock = accessible toilet with a hoist and changing table, these are intended for wheelchair users and those with profound disabilities and need the facility.