You can define moving loads or multi-step static vehicle loads to obtain shears, moments and deflections which can be accessed with the OAPI, but SAP doesn't offer any bridge design codes to my knowledge, only building and industrial design codes for steel and concrete design. CSiBridge offers bridge design.
SAP2000 v14has a module for bridge design, which evaluates the positive and negative resistence, and also the desig request. However, I cannot find the algorithms to obtain the same results through SAP2000 OAPI.
