Using Google maps to calculate a 'Roundtrip'

[mr10]

I'd like to be able to calculate a roundtrip in Google Maps, for e.g. running or cycling.

The idea would be to choose a distance (10km, 15km, etc) and then to calculate a few possible routes going from and returning to a set starting point

I'm having a hard time finding where I should start my search, or if this idea is even possible to implement.

Would anyone be so kind as to point me in the right direction?

Kind regards,
Maarten

[Marcelo]

If you go out half the distance and then return by backtracking on the
same route then you can do something similar to my V2 driving radius
example:
http://maps.forum.nu/gm_driving_radius.html

A round trip with a different return route is slightly more complex,
but you get the idea.

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Marcelo - http://maps.forum.nu
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