There's probably no need for tourists to take buses in Tehran. But for those living and working in the city they are a great help. Private taxis are unaffordable for most and even shared taxis are expensive for many. So the bus - being practically a free ride - is a necessity.
Tickets are bought from manned (usually an old man!) kiosks at major transport intersections and they cost 200 Tomans (about $0.20) for 10.
One thing that might bother foreign visitors is the sex segregation. Women ride in the back and men in front. Some might find it ironic that in minibuses and shared taxis no such pains are taken to separate men and women.
There are no signs in English and I've only once ever seen a map that showed bus routes - labelled, of course, in Farsi.
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