Design diaphragms with bolted connections at stiffener locations and connected directly to stiffeners without the use of connection plates whenever possible. Generally, a “K-frame” detailed to eliminate variation from one diaphragm to another, is the most economical arrangement and should be used. For straight bridges with a constant cross section, parallel girders, and a girder-spacing-to-girder-depth ratio less than two, an “X-frame” design is generally the most economical and must be considered.