What are the common types of roof and bridge trusses?

Common roof trusses include Pratt (diagonals in tension), Howe (diagonals in compression), Warren (alternating diagonal directions), and Fink (for steep roof pitches). Bridge trusses include Pratt, Warren, K-truss (for longer spans), and through vs deck configurations. The choice depends on span, loading, aesthetics, fabrication ease, and whether compression members can be adequately braced.