This work item incorporates two related revisions to the standard: Revision Item 1) eliminate minimum As6 reinforcing Consistent with the recently adopted provisions of Section 184.108.40.206.2 of the AASHTO LRFD Bridge Design Specifications, Sixth Edition 2012 with 2013 Interim Revisions, this revision eliminates the requirement for longitudinal distribution reinforcing in the top of the top slab (As6 reinforcing). The revision is based on research performed at the University of Texas at Arlington which showed that there is no flexural tension in the longitudinal direction (perpendicular to the span) of precast box culverts. Revision Item 2) expansion of the C1577 design tables The current tabulated designs for 11ft and 12ft spans only list even rises from 4 ft to the design span (4ft, 6, ft, 8, ft, etc.). In response to requests from state DOTs and industry producers this revision adds the odd rises ( 5ft, 7 ft, 9 ft, etc.) to complete the matrix of sizes in the tables.