In this paper, the authors will promote the modal shift policy of freight transportation based on the efficiency from trucking to shipping in Japanese domestic routes. As against an individual estimation for effect of consignor's efficiency including tradeoff between transport cost and delivery time, we tried to seek for a criterion of the estimation and its specific value on some consignor group from a statistical standpoint, and also according to the overall evaluation method for usual transport mode choice. As a result, we propose a method to find weighted values between transport cost and delivery time, in which the criterion is the diverging point from minus to plus in effects of the efficiency. Then the weighted value is calculated by applying to cases of modal shift which the Ministry of Transport (the Department of Transportation) has published. Using of this value, we further study possibilities of improvement on efficiency of the modal shift.