The next step is a refinement of feasible alternatives. This requires additional work
sufficient to prepare an environment document. This could include such items as approximate
construction costs; alignment and profile studies; typical section development; preliminary
designs for geometric layout, drainage, right-of-way, and utilities; location of
interchanges, grade separations, and at-grade intersections; preliminary bridge designs at
critical locations; channel work; air, noise, and water studies; flood hazard evaluations;
and other supplemental studies and right-of-way information. Once again, input is sought
from the public sector through advertisement and public hearings.
Figure 2.1 shows the corridors for the feasible alternatives for an 11-mi relocation
of U.S. 30 in Ohio (Ref. 13). The map is part of a study evaluating crossroad treatment
for each alternative. Figures 2.2 and 2.3 show the projected crossroad treatments for the
various alternatives. The options are (1) interchange, (2) grade separation, or (3) closing
roads with cul-de-sacs. Since the proposed segment will be a limited-access highway,
the option of at-grade intersection was not considered. Figures 2.4 and 2.5 show current
and 20-year projected traffic volumes for all roadways. These are examples of maps
used in the study of feasible alternatives.
After consideration of all the input and comparing the benefits and disadvantages of
each alternative, the next step is to make a selection of the recommended alternative.
This selection is certified by the state’s transportation director. Following approval of
the environmental document, the project may proceed to the design phase.