Suspension	Arch	Cantilever
Hinge	Can be used pretty much anywhere on the bridge. You will have to cut through the trusses and include a bit more structure.	Can be added to either side of the bridge but will need structure to support it.	Can only be added to the cantilever. Will need structure to support.
Pulley System	Can easily be added to any part of the bridge.	Can easily be added to any part of the bridge.	Structure is needed in this bridge to support the pulley system. Bit of a problem.
Gears	Can be added anyway to the bridge.	Can be added to either base structure of the bridge.	Can only be added onto the support of the bridge.

3 x 3 Table