This study evaluates the shear behavior and capacity of the precast concrete box culverts subjected to HS 20 truck wheel load. The most critical culvert behavior was considered by studying culverts subjected to zero depth of the fill and placed on a rigid bedding material. Full-scale experimental tests, with wheel load placed at the most critical shear location, were conducted on 24 typical precast concrete box culverts designated as per ASTM C 1433- 05. The test results further indicated that flexure governed the behavior up to and beyond AASHTO 2005 factored load.Three-dimensional nonlinear...