In Japanese expressway tunnels, the longitudinal ventilation method using a jet fan is mainly used for exhausting smoke during a fire. Usually, when there are no stopped vehicles downstream of the fire source in the tunnel, the smoke is exhausted downstream to maintain the evacuation environment on the windward side. However, when there is a stopped vehicle on the leeward side of the tunnel, it is necessary to suppress the movement of smoke to maintain the environment until evacuees complete their evacuation. At this time, there is a concern that the fire disaster will spread if there is a mistake in the smoke exhaust. For this reason, it is desirable for the control to be automatic, without the intervention of an operator. To solve these problems, a new smoke control system method was proposed from the viewpoint of early detection of fire, and its superiority was confirmed via computational fluid dynamics (CFD) evaluation of smoke behavior during a fire. Based on these findings, this paper reports the results of an evaluation experiment in a full-scale tunnel.