Communication and control represent a small but important part of the overall transportation problem. Although communication and control differ depending on whether land, sea, or air transportation is involved, there are broad areas of similarities between many of the principles being used for these applications despite the differences in the equipment and detailed practice employed. Control is used to refer to such varied meanings as the control of the translation and rotation of a single vehicle and its associated stability, the control of the propulsion plant, the control of the necessary auxiliaries of voltage, temperature, pressure, etc., and the control of multiple vehicles by either local or centralized methods. Attention is given briefly in this paper to each of these aspects of control. Many of the principles involved are illustrated in more detail elsewhere in this issue where specific transportation control systems are described. Communication is used to refer to the means for tying together the different parts of the transportation system located at different places but sharing a common set of facilities at similar or different periods of time. Communication is required to provide adequate sensor information about such conditions as the position, velocity, and acceleration of the various vehicles involved in the system. Communication also may be required to establish guideways for the plane, ship, train, or car to move by. For multiple vehicles, commmaication is needed to exchange information between the control center and each of the vehicles concerned. Communication and control can have a vital role on such overall characteristics of a transportation system as safety, capacity, reliability, speed, and economy. It is in the fields of control and Communication for multiple vehicles that the greatest effort will be required in the immediate future.