Yes, I DID THAT ONE! And it was thrilling indeed. I haven't been to the Himalayas yet, I would have reached it if I didn't have an accident which caused me to break off my sabbatical that should have taken 9 months, but instead lasted for 'only' 2. (If interested in the story, my first posts tell this in detail.)

A photo documentary about local transport is a great idea actually :-)

As for photographing people, which I've done a lot as I used to be an enthusiastic street photographer: in the Netherlands at least streets are public spaces and you can take pictures of people and publish those without permission. I believe in Europe only Hungary has an official law that says you have to ask for permission before taking a picture of a person on the streets.

Privacy only comes up in rare cases: if a person is in a specific profession and has been photographed in a 'damaging' situation they might win in court to let a photographer remove the picture from media, but they will have to do a very convincing argument as to why that picture would damage their professional/private life.

I personally keep rules for myself: I never ask (this ruins that moment I wanted to take the picture off), if the person notices me I smile and wave and if they seem interested I approach them to show them my picture and give them my business card so they can contact me to get a copy of the picture. If the person doesn't notice I often let it go.

Lastly, if I feel I would personally be embarrassed if someone published a picture of me in the same context I don't publish it either.