Page 86 - Highway Engineering Handbook Building and Rehabilitating the Infrastructure

HIGHWAY LOCATION, DESIGN, AND TRAFFIC 69

● Minor safety-type improvements, such as guiderail replacement or installation of
breakaway sign hardware
● Outdoor advertising control programs
● Bicycle or pedestrian facilities provided within existing right-of-way
All projects that do not fall into the above categories must undergo additional
evaluation in a preliminary development phase.

2.1.4 Preliminary Development Phase

Two types of projects are considered here: (1) projects that involve studies outside the
existing corridor or where a facility for more than one alternative mode of transportation
may be involved, and (2) projects where feasible alternatives are limited to the existing
corridor but did not qualify to pass directly to the design phase. The main difference
between the two as far as processing is concerned is that the first group has not yet
narrowed its alternatives down to feasible alternatives.
In each case, a project inventory is developed. This information includes historical
sites; public recreational facilities; school, church, fire, and police districts; proposed
development; land use; existing and other proposed transportation facilities; prelimi-
nary traffic assignments; and other similar social, economic, and environmental features,
which are pertinent to the area under study. Using this information as a guide, all pre-
liminary alternatives are developed together with documentation of the anticipated
effects on community, preliminary cost estimates, and other technical considerations.
Advantages and disadvantages of each alternative are studied. Where appropriate, coor-
dination with other modes is considered. The “no-build” alternative is also considered
and provides a reference point for defining potential beneficial and adverse impacts.
Public hearings are held to gain input from the local public in the affected areas.
Following an evaluation of all input received, alternatives are weighed and only those
considered to be feasible are forwarded to the next step. From this point on, all projects
in the preliminary development phase are on the same path.
Among the environmental concerns which must be considered for each alternative
are the following (see also Chap. 1):
Air quality. A study of the effect of a proposed transportation improvement on
the quality of the air
Historic or prehistoric. A study of the effect of the proposed transportation
improvement on historic or prehistoric objects or on lands or structures currently
entered into the National Register or which may be eligible for addition to the
National Register
Endangered species. A study of the effect of the proposed transportation improve-
ment on rare or endangered plants or animals having national or state recognition
Natural areas. A study of the effect of the proposed transportation improvement
on natural areas designated as having regional, state, or national significance
Parks and recreation. A study of the effect of the proposed transportation
improvement on publicly owned parks, recreation areas, or wildlife and waterfowl
refuges designated as having national, state, or local significance
Prime farmlands. A study of the effect of the proposed transportation improvement
on farmlands with high productivity due to soil and water conditions or having other
unique advantages for growing specialty crops