Closure to 'Live Load Radial Moment Distribution for Horizontally Curved Bridges' by Woo Seok Kim, Jeffrey A. Laman, and Daniel G. Linzell

The authors state that two and three AASHTO HS25 trucks and lane loads were applied based on the bridge width and that “a trial and error protocol was established for radial truck position to establish critical wheel load paths.” Further, that “HL-93 loadings were systematically placed at 305 mm 1 ft. increments from the outside girder.” This raises several issues. HS25 trucks are associated with the AASHTO Standard Specifications while HL-93 loadings are associated with the AASTHO LRFD Code. It is not correct to mix the two in an analysis. It is not clear if the two codes have been somehow combined. Both the AASHTO Standard Specifications, 17th edition, Article 3.6.2, and LRFD Code, 4th edition, Article 3.6.1.1.1, require that truck and lane loads be positioned within 3.65-m 12-ft. wide lanes. It appears that this requirement has not been met in this study.