This paper deals with the effects of reduction of CO2 emission by a Modal Shift from road transport to railway as a result of Transportation Demand Management (TDM). In Toyota City, roads are seriously congested because of commuter traffic by private cars. Local governments, companies and people in and around Toyota City are concerned about TDM to improve the road conditions. Double tracking of the Aichi Loop Railway (from Mikawa-Toyota to Shin-Toyota; 3.6 km), an important option of TDM, has been completed. This project has increased transportation capacity, 4 shuttle trains per hour have been operating since March 15, 2008. It is expected that 4,000 commuting passengers will shift from road traffic to the railway. The Model Shift will reduce CO2 emissions from transportation by private cars at least 1,500 ton per year. This project has been succeeded, 1,000-2,850 number of commuter passengers have been modal-shifted from private car to railway. JFL Classification: Q51, R41