City Traffic Simulator is, in fact, a tram sim; that is, you operate a light rail car in an invented European city.
There's a bit of a sim/tycoon aspect; you don't lay new lines, but you earn money by transporting passengers, with which you may purchase new tram cars. You start with the ability to run only one of several routes in the city, and unlock new routes by successfully transporting some number of passengers of different social classes.
As with most vehicle sims, it's not an intense game; the pleasure comes more from the feel that you're actually operating the vehicle, and from the scenery (photography of what I assume is the Czech countryside scrolls as your tram moves). Correct operation is surprisingly tricky, at least at first, however; trams, like all trains, have considerable inertia, so gear-changing to hit your marks takes a little effort. In addition, there are crossings with lights, and you are penalized money if you go through a red light or pass through a crossing at more than 30km/hr. You're also penalized if you don't stick to the tram's posted schedule.
On the whole, it's quite well done for what it is, impressively so for a lone-wolf developer; and while there are plenty of railroad sims, I don't know of any other sims of urban light rail. And it's both freeware and open source.
One word of warning; the file is hosted on a site which pops up ads -- many of them, if you aren't careful to click on the correct link ("click here", quite close to the bottom of the page).
