Originally Posted by godshammgod

As someone who works there (and lives 5 minutes away), I will caution you to choose your times carefully. The traffic can be heavy at times, which might force you to to slow down, etc. I'm assuming you're looking for an interval loop for Mount Washington.

If you're in the area, this might be a good option: http://ridewithgps.com/routes/941921

A nice two mile road, no stops, relatively flat. It's my solid choice for shorter intervals, though you would have to stop and turn at the end.