42.3    Material and Strength

The materials, design and construction of manholes, handholes, and other underground boxes shall be such as to provide sufficient strength to sustain, with a suitable margin of safety, the loads which may reasonably be imposed on them. Manholes and handholes in street areas which are subject to vehicular traffic shall be constructed to withstand H–20-44 highway loading as designated by the American Association of State Highway Officials. Floors of manholes shall meet the requirements of Public Utilities Code, Sec. 8054 (Also see Appendix B, Fig. 9, and Appendix D.) .