go out 78 east to loganville. after you go through the Main Street intersection it's a couple of lights ahead on your right, 160 Cown Street. (actually the fifth right, but only a couple of stoplights, maybe even only one). if i am not mistaken, there's a QT there on the righthand corner. the lefthand side will say highways 81/20. the signage is pretty good. but you can look it up on Mapquest with the address, right?

Here is a link that might be useful: here's a map