Mario, one of the other students in the WDDC class, created a website about his Figure Eight two-geared system.
Here is an excerpt from the site:
The Figure-Eight Drive is an implementation of a Retro-direct bicycle drivetrain on a hand-powered tricycle. It provides tricycle users with a reliable two geared system. Users can switch between the two gears by changing the direction of their pedaling, with both directions resulting in forward propulsion. Pedaling in the standard forwards direction provides users with an approximately 1:2.25 cruising gear, while pedaling in the reverse direction allows users to climb and maneuver easily with a 1:1 gear ratio. The tricycle can freewheel in the forwards direction, though no backwards movement is allowed. The steering column can be rotated 180 degrees, allowing one to ambulate and freewheel in reverse.