From Alex Blakely:
Russia also has the Trans-Siberian Highway, which is, with one caveat, the longest road in the world. In places the highway is several lanes wide and is covered in blacktop painted with bright, reflective lane lines. In other places it is just a meandering single-lane road with an uneven, severely pocked surface. The caveat is that, despite its name, the Trans-Siberian Highway doesn't actually transverse Siberia. It has a gap wider than most roads are long. That is, you can drive the Trails-Siberian east from Moscow, where the highway begins, for about 3,500 miles before the road peters out past Lake Baikal. Then for about a thousand miles there is pretty much nothing but trees. The road picks up again above what used to be Manchuria and wends the remaining thousand miles or so to Vladivostok, on Russia's far eastern shore. You can think of the Trans-Siberian as two finished highways with a thousand miles of forest between them, or you can think of it as a single unfinished highway that is a quarter the circumference of the Earth. Either way, though, you can't drive from Moscow to Vladivostok.