[gen220]

Gotcha, that's disappointing.

I think my friends were riding along the Charles River, for what it's worth. They're more occasional bike commuters (once or twice per week) than a real serious bunch, and I don't know their start/end points.

Rail-to-trail appears to be how most longish (10 mile +) bike paths come into existence in the northeast, from my observations. There's a lot less "free space" to work with than other parts of the country, since the land is so developed / dominated by automobiles.

[rory]

I used to commute on the Charles River bike paths and esplanade. It is actually pretty great for commuting from the Allston and Harvard areas downtown, but that experience doesn't generalize to other routes around the city. And the last half mile or so to get to your actual office can be pretty perilous.