ACHIEVING the ambitious aim suggested by the title of this paper would involve, first, defining what is meant by the term structure; second, developing some notion of priorities as to what types of effects are the most meaningful for discussion and analysis; and, finally, devising some way to trace the diffused effects of freight rates and rate changes throughout the economy in such a way that meaningful relationships may be identified net of forces other than those attributable to freight rates. Rather than attempt the impossible I shall follow a somewhat more modest approach which will include a brief examination of how the existing transport rate structure has evolved, some questions that might be raised as to assessing the impact of transport rates on the agricultural economy, and a concluding discussion of some speculative implications for agriculture of some current rate issues. In order to make sense out of a rate structure, it is necessary to reduce the transportation market ultimately to a series of pairs of geographic points. Specific rates can then be ascertained for specific routes for specific commodities for specified levels of service for all available transport modes under the entire array of relevant conditions confronting shippers. The resulting tabulation of information might then be referred to as a rate We have yet to determine in quantitative terms relevant for economic analysis how to characterize the rate structure. The difficulty in making the transition from an identifiable rate for specific geographic points to a general rate structure, however, does not eliminate the fact that decision makers must, in fact, act as if it were possible to make such a transition. Individual rates can usually be identified; the problem is one of devising a relevant summary of rates. In this paper it will be necessary to refer to rate structure only in gen-