I've started to have some success with MapMyRide.com and the "Route Genius." Recently introduced, still needs some dev work, but not bad at all. Analogous to iTune's "Playlist Genius," it takes a few parameters (eg: start location, desired ride distance, starting direction) and generates a suggested route, which you can then send to your smartphone client app and take on the road.
Again, it's fairly new and needs some "evolution," but I've used it a couple of times with success. Be aware that there is a LOT about your local region that MMR server doesn't know, and you'll have to take a critical eye to the suggested route before you just go out and do it. For example: "no, that route 22 is NOT bike friendly." or "No, that part of that city is no place for a skinny guy in lycra." I've also used the Route Genius with success in more rural areas.