Funny you should post this,
@J.R. I too have cycling maps on my mind.
My pet peeve right now is this: google maps turning bicycling layer on and letting google calculate routes using the bicycle as the mode of transportation still routes a ride on roads that, while technically may be considered "bicycling friendly", the road is dangerous for cyclists and should not be used. Thus, google is not truly cycling friendly and it's not calculating the safest cycling route. There are various greenway paths that sometimes add 1 extra mile but could be the safest way for a cyclist to get from point A to point B. But google doesn't consider that.
My wish: a cycling app (that works on Android and on web) that will calculate the "safest" route for a cyclist, keeping the cyclist off of roads that do not have bike lanes. LaneSpotter, is an app that is on iPhone that will supposedly do this. They have an android version that has gotten 1 star reviews as it's terrible and a fraction of what the iphone app has (allegedly).
In looking at the roads in my area, I now realize I need to utilize the sidewalks on the busier streets (it's legal in my area for bikes to use sidewalks). I don't go faster than any cyclist would on a sidewalk. There's no reason for me to put my life in danger if there isn't a cycling lane available.
I don't have the desire to try and map out the 'safest' route possible because my geo area is a real mishmash of safe greenways and regular roads.