A&O’s foundation is grounded in bridge design, with deep and varied experience among the professional staff. A&O’s experience ranges from pre-engineered greenway bridge foundations to multi-level urban interchange curved-girder steel bridges. Greenway bridges have included natural timber and glue-laminated materials with composite recycled decking.  DOT bridges have included conventional construction materials including reinforced concrete, precast prestressed concrete, and structural steel.

One special project that required an innovative solution to a challenging set of constraints was the floating swing-span bridge, created to transit the historic Dismal Swamp Canal in South Mills, North Carolina. It allows pedestrians and vehicles to cross the Canal for access to the Dismal Swamp Visitor Center, but opens and swings away to let boats through.