I've been experimenting in somewhat cycling route constrained Rhode Island -- Try getting from Providence to southern Warwick without going on a busy road with an average speed over 40 and no shoulders). I've gotten some very good suggestions for alternate routes that avoid some of the busiest roads when possible. This beats Googles "avoid highways" options by leaps and bounds. The only trick is that when entering the start and end addresses, it is necessary to hit the options button and change to By Bike. This choice is confirmed on the route results screen, making it easy to see what options are selected.
My only gripe is that they don't implement functionality to use the mouse's scroll wheel to zoom in and out on the map.