Routes for bicycling
Westchester has some nice off-road riding on paved paths -- check out the Westchester County Trailways.
There is also a long trail with some accessible unpaved mostly-off-road sections that some people ride on: Old Croton Aqueduct.
Our early experiences with exploring the roads of Westchester county were that we spent lots of time on narrow two-lane roads with much car traffic. Since then we've started finding some quieter roads, and some rather pretty roads. But we have not found it easy to link up lots of these quieter and prettier roads into a nice loop route.
Therefore we advise not trying to explore the roads based on just trying out what might look good on a map. If you want to bicycle in Westchester county, we suggest getting some advance knowledge from those with some experience -- try Other People's Routes and more links below -- and you can learn from people's stories in the trip reports.
Something we are working on (as of November 2002) is a one-way sequence of roads that go north to south through Westchester, sampling some of the pretty views by the Hudson River (and continuing on to the Bronx and Manhattan). At this point it's an exploratory adventure -- see the East side of the River parts of this:
Routes reached by Trains
One very helpful thing about Westchester county is that it is served by two major train lines from New York City -- so this can be a convenient way for many bicyclists to reach Westchester county. See Routes from Trains -- but note that the Metro North bicycle rules have restrictions and require a special permit for a bicycle -- which require some advance planning.
Using the Metro North trains makes possible some interesting one-way routes between train stations. Here's some ideas for experienced road riders with good traffic-handling skills to consider:
For some possible ideas about specific roads, see the various other routes linked from this page (like sections of GWB to Bear Mt Bridge Loop for train stations along the Hudson line of Metro North), also some of the trip reports.