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Description of five steps of highway development
Highway design is only one element in the overall highway development process.
Historically, detailed design occurs in the middle of the process, linking the
preceding phases of planning and project development with the subsequent phases
of right-of-way acquisition, construction, and maintenance. While these are
distinct activities, there is considerable overlap in terms of coordination
among the various disciplines that work together, including designers, throughout
the process. It is during the first three stages, planning, project development,
and design, that designers and communities, working together, can have the greatest
impact on the final design features of the project. In fact, the flexibility
available for highway design during the detailed design phase is limited a great
deal by the decisions made at the earlier stages of planning and project development.
This Guide begins with a description of the overall highway planning and development
process to illustrate when these decisions are made and how they affect the
ultimate design of a facility. Although the names may vary by State, the five
basic stages in the highway development process are: planning, project development
(preliminary design), final design, right-of-way, and construction. After construction
is completed, ongoing operation and maintenance activities continue throughout
the life of the facility.
Planning The initial definition of the need for any highway or bridge improvement
project takes place during the planning stage. This problem definition occurs
at the State, regional, or local level, depending on the scale of the proposed
improvement. This is the key time to get the public involved and provide input
into the decision-making process. The problems identified usually fall into
one or more of the following four categories: 1. The existing physical structure
needs major repair/ replacement (structure repair). 2. Existing or projected
future travel demands exceed available capacity, and access to transportation
and mobility need to be increased (capacity). 3. The route is experiencing an
inordinate number of safety and accident problems that can only be resolved
through physical, geometric changes (safety). 4. Developmental pressures along
the route make a reexamination of the number, location, and physical design
of access points necessary (access). Whichever problem (or set of problems)
is identified, it is important that all parties agree that the problem exists,
pinpoint what the problem is, and decide whether or not they want it fixed.
For example, some communities may acknowledge that a roadway is operating over
its capacity but do not want to improve the roadway for fear that such action
will encourage more growth along the corridor. Road access may be a problem,
but a community may decide it is better not to increase access, Obtaining a
community consensus on the problem requires proactive public involvement beyond
conventional public meetings at which well-developed design alternatives are
presented for public comment. If a consensus cannot be reached on the definition
of the problem at the beginning, it will be difficult to move ahead in the process
and expect consensus on the final design. Planning Occurs at Three Government
Levels State Planning. At the State level, State DOTS are required to develop
and maintain a statewide, multimodal transportation planning process. Broad
categories of highway improvement needs are defined, based primarily on ongoing
examinations of roadway pavement conditions and estimates of present-day and
20-year projections of traffic demands. In addition, each State is required
to conduct biennial inspections of its major bridges (and similar, less frequent,
inspections of minor structures) to determine their structural adequacy and
capacity. In a number of States, regional transportation plans for multiple
counties are prepared within the context of the statewide planning process.
Every few years, the State selects improvement projects based on the longrange-plan
and includes them in the Statewide Transportation Improvement Program, or STIP.
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