As the relaxation measure of the road congestion, we review and are implementing the introduction of the TDM policy of the time distributed type. However, when these policies are widely introduced, the part of the business trips which occurred after the commuting time band ended so far gets to occur at the commuting time band, too. In this paper, we think the optimal allocation problem with road traffic capacity to the conflict of the commuting traffic and the business traffic under the flexible work hours. We have proposed the theoretical model which demands the time distributions of the commuting and the business traffics.