map or derived model was possible, and allowed for the rapid comparison
of all alternatives.
The use of computer-aided techniques reduced the time required for the
study. First, they allowed for a more rapid generation of a very large
number of alternatives reflecting a variety of constraints. This
resulted in the draft Environmental Impact Statement (EIS) being prepared
in just over one year, rather than the two years normally expected.
This occurred in spite of the complexity and controversy surrounding
this project. .
Furthermore, the final EIS was produced within a further six months, or
approximately 1 1/2 years from project initiation, rather than the more
normal 2-3 years, and final government approval for this project occurred
in slightly over 2 years from project initiation. Within this period a
contentious situation was transformed into one where there was substan-
tial agreement.
Conclusions
It seems probable that computer-aided planning systems incorporating at
least some of the GCARS System elements will have a large role to play
in future planning methodology. Computer-aided systems are particularly
attractive in analyzing complex or ambiguous factor interactions and the
trend to greater complexity and ambiguity of location factors seems well
established. Recent studies have shown that, in the highway field at
least, early project planning is constrained by environmental assessment
considerations. Although new highway construction appears to be on the
wane, demands for new electrical transmission lines and for oil, gas, or
coal slurry pipelines seems to be on the rise. The location analyses for
these transportation forms can be ideally handled by these GMAPS-GCARS
systems.
The prediction of increased importance and acceptance of computer-aided
planning systems such as GMAPS-GCARS is based on three trends presently
underway: -
1) the availability of good quality, computer-processable "data banks"
2) the development of "companion" computer systems to handle other
aspects of transportation planning and design
3) the widespread installation of "time-sharing" computer systems
with interactive terminals.
References
1. Alexander, C. and Manheim, M.L., 1962, "The Use of Diagrams in
Highway Route Location: An Experiment", Civil Engineering Systems
Laboratory Research Report R62-3, Massachusetts Institute of
Technology, Cambridge, Massachusetts.
2. Ayad, H., 1967 "System Evaluation by the Simplified Proportional
Assignment Technique", Thesis, Ph.D., Purdue University (Unpub.),
Lafayette, Indiana.