If I were to explain to an American the meaning of marshrutnoye taksi, I would start with a translation, “fixed-route taxi” but have a harder time describing how this means of public transportation actually works. But now that I’ve come across a Turkish version of that, the task would be accomplished in no time (source):
Dolmus (literally full of passengers) is a kind of shared taxi which, sometimes takes the form of a large car, a station wagon, a regular taxi or a minibus. It follows a specific fixed route. Passengers pay according to the distance traveled and can get in and out whenever and wherever they want to by informing the driver. It is a very practical means of transport and much cheaper than a taxi. The dolmus fares are determined by municipalities according to distances.
Russian dolmuses are almost always mini-buses, almost always Gazelles produced by the GAZ auto factory, which started making them in the mid-1990s and has been quite successful with this model. Fares are not directly set by municipalities — not in Moscow anyway — but are strongly influenced by municipal bus fares, since fixed-route taxis are buses’ direct competitors. Fares are usually flat within the city limit.