(l) As for such construction section in underdeveloped area as Sendai-Ichinoseki Section, quite different results were obtained according to the preconditions whether a set of long time-horizon & low discount rate will be adopted as exogenous variables, or a set of short time horizon & high discount rate will be. Former case is advantageous to the route in congested urban area, and latter in hilly area. (2) Circumferential section in metropolitan area is profitable to the private investment not to the public (under some preconditions). (3) For Towada-Aomori Section, we obtained the result that it is sufficient to accommodate ordinary road of 2 lane (not expressway) even in a considerably later period, and moreover it is not affected by the option which should be adopted, long time-horizon & low discount rate or short & high. In case of being free from political constraint of improving regional income disparity, such a drastic solution is obtained. In addition to parametric analysis of optimum solutions mentioned above, we get imputed prices to constraints which will give a clue to the investment planning hereafter. Finally, in our empirical study, stress will be put on the general derivation of investment criteria, and is, so-called, a pilot study in which its necessary components, i.e., economic effects are calculated in a conventional method (World Bank type).