Rule 9.2.3:  Parts of the bridge (including fasteners and parts that bear on the ground) must not extend beyond the vertical plane defined by the ends of the decking support surfaces at each end of the bridge.

Common Error:  Most of the violations have to do with fasteners or cross pieces extending beyond the plane defined in the rules. 

A level or a plumb bob can be used to verify that a part of the bridge extends beyond the decking support.