This section builds upon the early phases described in and provides information on the design phase of highway and road construction projects. It provides a brief reference to items initiated in the 30 percent design and more details on items developed as the engineering progresses through final design. For all design elements, the LG and its design engineer must reference TxDOT’s guidance manuals (such as the ) or other TxDOT-approved manuals or standards to find details for incorporating TxDOT and Federal Highway Administration (FHWA) design requirements into the project design.