If you click on a section of the generated route a dialog box will appear allowing you to rate that section's perceived safety on a scale of 1-7, this will affect future generated routes. Also the system tends to prefer residential streets and cycleways over major roads, and prefers roads with bike lanes or signed bicycle routes.
OpenStreetMap
Discussion
Kommentti käyttäjältä wieland 22. March 2010 klo 08.58
How do they know, which way is safer?
Kommentti käyttäjältä andrewpmk 23. March 2010 klo 03.51
If you click on a section of the generated route a dialog box will appear allowing you to rate that section's perceived safety on a scale of 1-7, this will affect future generated routes. Also the system tends to prefer residential streets and cycleways over major roads, and prefers roads with bike lanes or signed bicycle routes.
Kommentti käyttäjältä wieland 23. March 2010 klo 21.06
@andrew: Thanks