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.