Is it obligatory to quit working as a bus driver if the passengers are drunk or drink alcohol during the night, especially in a non-Muslim country where no other work alternatives are available?

It is not forbidden for a Muslim to work as a public bus driver, unless the buses are specifically designated for transporting passengers to places where forbidden acts are committed. However, the presence of passengers who drink alcohol does not make the work forbidden, because the fundamental purpose of a driver's work is to transport passengers, which is a permissible act.