How does Google Maps estimate cycling times Google Maps has a bicycling routing option in beta. It does seem to do a good job routing in my town by using streets with bike lanes where possible and avoiding going up steep inclines directly.

But I'm curious how it estimates travel time. For cars, it seems to use the speed limit with a proprietary  fudge factor that uses historical and current traffic conditions. 

But for bicycles, what is it using to estimate travel time? There's considerable spread in terms of speed between the fastest Strava PR (personal record) seekers and the slowest bike moms with trailers - maybe even as great as 2-3x difference. 

Has anyone figured out what the algorithm seems to be doing in terms of cycling times? Does it take into account the user's own cycling speed? Has Google said anything re: this?
This site seems to have some good answers to your questions. It says


  Google assumes a baseline moving speed of around 16km/hr (10miles/hr) regardless of trip distance.


but if you read more you can see there are adjustments to that baseline. For some routes where I've actually compared, I divide the Google cycling time by 1.5 to get an estimate of how long it would take me, but I used to race pretty seriously.