In Japan, a new project for reducing CO₂, called "Energy ITS project" has started since 2008 by New Energy and Industrial Technology Development Organization (NEDO) for reducing CO₂ emissions. This project aims to develop techniques for the autonomous platooning of heavy-duty trucks to reduce their air resistance in expressway driving. Platooning needs lateral and longitudinal control. This paper describes novel lateral and longitudinal control. Lateral control method is based on path following. Longitudinal control method uses information acquired from the front and rear trucks by inter-vehicle communication. And a steering control methods using feedfoward control to deal with a road cant and a deviation from a target course by a disturbance are proposed. The experimental results of autonomous platooning are provided to evaluate the effectiveness of the method. In this experiment, the platoon is composed of four trucks, and two kind trucks are used.