Subways can be a great way to get around a big city, but of course you have to understand their layout, first. That can be a challenge, particularly if you leave it until the last minute, and are left peering at a huge map on a tiny smartphone screen (that’s if you can get a signal at all). But plan ahead with a little help from qMetro and your life could be very much easier.

An open source tool available for Windows, Linux, OS X and more, qMetro comes bundled with 23 maps covering subways in many big cities: Amsterdam, Beijing, Berlin, Brussels, London, Madrid, Moscow, New York, Paris, Tokyo and others. But if that’s not enough, there are something like 200 maps available online (and in theory, at least, you can even create more yourself).

At a minimum, you might use qMetro just to open and display a static map of your chosen subway. Navigation is easy, you can spin the mouse wheel to zoom in and out, or click and drag the map to pan around. Your current map scale and position will by default be saved, too, so you can close the program, come back later and carry on where you left off.

The qMetro maps aren’t just images, though. Find and click on one station, and all the others on the map will display a figure indicating how many minutes away they are.

Browse the map, click a couple of stations, and qMetro will calculate your best route right away

And if you click a second station then the program can even calculate a route for you, including any transfers and the total travel time.

QMetro does have a few interface irritations. If you click a couple of stations then the program correctly displays the route between them, for instance. But if you then accidentally click anywhere in the map window, that route is immediately cleared, which can be very annoying.

Some functions don’t work as you expect. There’s a Search window where you can enter station names, for instance, and we thought the obvious application for this would be to zoom in on, or highlight whatever station you need. But we were wrong: it doesn’t do that at all. (We’re not entirely sure how it works, in fact, and the lack of any documentation doesn’t help.)

And more fundamentally, you’re more likely to need this kind of functionality on a mobile device than a desktop. The program doesn’t even include a Print option so that you can take a route along with you (the best it can do is copy a route to the clipboard, so you can paste and print it elsewhere).

Still, qMetro’s core functionality has a lot of promise. There are plenty of maps. They’re open format, so it’s relatively easy for others to add more. The route calculation engine seems reliable, from what we can see (although that requires major testing to tell for sure). And just a few relatively small tweaks, like providing more ways to save and share your route, would make the program much more useful. If you’re interested in metros or maps then you should take a closer look.