"I must admit regular photos taken on the bus seems a bit weird to me"

Let me see now let us have a look at those who made a career out doing something similar every day for years on the New York Subway:

Bruce Davidson - Subway - photographic record of subway passengers from 1980 to 1986 - work highly acclaimed.

Reinier Gerritsen - "The Last Book" - for 13 weeks over the course of three years Gerritsen travelled the underground from 8 a.m. to 7 p.m. taking pictures of people on the subway reading books - work highly acclaimed.

Walker Evans - "Subway Portrait" - between 1938 and 1941 he secretly photographed passengers using a hidden camera - work highly acclaimed.

Dare say there are many other examples elsewhere in the world.