Abstract: A reinforced metal box culvert is provided which has the standard crown, opposing sides and opposite curved haunches. The culvert is characterized in having continuous corrugated metal sheet reinforcement secured to at least the crown of the culvert and extends the length of the culvert which is effective in supporting the load. The corrugated reinforcement has a profile which abuts the crown corrugations with the troughs of the reinforcement being secured to the crests of the corrugated crown. The corrugated reinforcement sheet has a curvature complementary to the corrugated crown to facilitate securement. The continuous reinforcement, as secured to the culvert in an uninterrupted manner, provides an optimum load carrying capacity for selected extent of reinforcement provided by the reinforcement metal sheets.