GV27 makes a lot of good points, and I hope that Google will have a way to take input from the users to upgrade the quality of their suggested routes. Real people sharing real information will be much more critical to this than for driving or even pedestrain route mapping. Cyclists also have a huge range of ability and comfort zones, so eventually it would be nice to see the 'bicycle' option be more customizable (road/mountain bike, top speed of traffic you're willing to mingle with, preferences to avoid stop signs).