The EmX is kind of like a rail line without the rails. It travels down a special road bed using speically designed buses. This road bed is separated from the rest of the road and is only open to the EmX buses so, once the EmX leaves the local street, it behaves rather like a rail line.
Just like MAX, the first line was built to the nearby community to the east. More to come, by the looks of it–on the west, naturally.