I had a bit of a problem with wanting to pass water very often - I never leaked, just felt uncomfortable. I thought I might have a prolapsed bladder, as my mother and sister had both had operations for this. My doctor referred me to a specialist incontinence clinic (I was still in the UK then) and I was surprised to find a young male nurse was running it. Given that many patients would be more mature women, I thought this was a bit insensitive.
He asked me various questions and told me I probably just had an irritable bladder (I was certainly a bit irritable myself by this time) and I should train it by holding on as long as I could, cutting down on my cups of tea, and making sure I got rid of every last drop by leaning forward, waiting 20 seconds, then trying again.
The problem resolved itself physically when I took up long walks, although there is still a psychological element, that makes me want to use the loo whenever I am going out. I also follow my mother's advice - don't go when you need to, go when you can - so if I go into a cafe or supermarket that has toilets, I use them.
In the mountains, I have become expert at finding nice, private places - pine forests are useless! If driving in France, I look for a MacDonalds - they are on the outskirts of nearly every town and you don't have to eat in them.
Some French women use the 'entre deux portes' method by the roadside - open both front and rear car doors to give some privacy. In France, and more rarely in Switzerland, you still find the 'squat' type , even in motorway services - which would not be so bad if they provided any grab rails.
At least it is rare now to find unisex toilets in bars or restaurants - I remember my first visit to Paris, in quite an up-market restaurant, being embarrassed to find there was a 'pissoir' being used by a man who bid me a pleanst 'Bon soir, Madame' before I dashed into the cubicle.