The decision-making process that precedes construction is called planning. Briefly, this process is the development and establishment of a set of goals, the selection and approval of a set of improvement projects, and the investigation and design activities required to realize the goals. This process leads to the actual highway improvement activities of land acquisition or site construction or both. The first step of goal formulation is called comprehensive planning. The second, third, and fourth steps are called project development functions, which are the detailed implementation of the transportation plan. There are four steps involved in project development: (a) long-range planning; (b) design investigation, the refinement of the long-range planning; (c) design process, i.e., the management procedure and engineering process for producing contract plans for an improvement project; and (d) precontract administration, the processing of the contract plans prior to execution of the improvement construction. The project development system has been well received because of two major characteristics: the policy statements and revisions can be in the hands of users within 36 hours, and formal documentation in the design manual can be easily revised and updated without upsetting the overall organization. Computer-aided design, the highway design system, will be accomplished by systematic development of computer technology toward the goal of creating a numeric surface approximating the earth's surface on which any number of designs may be superimposed so that the optimum design may be achieved. /author/
Abstract