Traditional covered bridges were essentially side truss bridges. Most modern covered bridges use conventional side girders or deck girders. The covering is simply added to the top of the bridge.

Side Girder (Timber)

Typical span 50 to 90 feet

Additional Pictures:

Example sketch of a covered side girder bridge

Deck Girder (Timber)

Typical span 40 to 80 feet

Additional Pictures:

Longitudinal Glued-Laminated Deck

Typical span 10 to 25 feet

Additional Pictures:

Example sketch of a covered longitudinal glue laminated deck bridge

Traditional Covered Bridge

Typical span 40 to 300 feet