Here is a little hour-and-a-half training ride I did yesterday after work. This route works pretty well early and late season when one is forced by short days to ride during rush hour. Most of the route goes against the prevailing traffic (excepting heading out on Providence Road but once over the beltway, traffic is light).
This loop has several good climbs with Notchcliff (aptly named) being the biggie.
http://www.bikely.com/maps/bike-path/notchcliffshorty