A travel control device comprising: a first inter-vehicle distance acquiring unit configured to acquire, in a position lateral to a vehicle on an adjacent lane adjacent to a lane on which the vehicle travels, a first inter-vehicle distance that serves as a target for a lane change of the vehicle and is an inter-vehicle distance between a first preceding adjacent vehicle in a lateral forward direction of the vehicle and a first subsequent adjacent vehicle in a lateral rearward direction of the vehicle; a second inter-vehicle distance acquiring unit configured to acquire a second inter-vehicle distance that is at least one inter-vehicle distance of an inter-vehicle distance between the first subsequent adjacent vehicle and a second subsequent adjacent vehicle as a vehicle subsequent to the first subsequent adjacent vehicle and an inter-vehicle distance between the first preceding adjacent vehicle and a second preceding adjacent vehicle as a vehicle preceding to the first preceding adjacent vehicle; a lane change possibility determining unit configured to determine a possibility of the lane change from the lane on which the vehicle travels to the adjacent lane by using the first inter-vehicle distance; the travel control device being characterized by a waiting necessity determining unit configured, when the lane change possibility determining unit determines that the lane change from the lane on which the vehicle travels to the adjacent lane is not executable, to determine presence or absence of a possibility that the first inter-vehicle distance will extend to a length that allows for the lane change by using the second inter-vehicle distance, to determine that waiting is necessary when it is determined that there is the possibility that the first inter-vehicle distance will extend to the length that allows for the lane change, and to determine that the waiting is unnecessary when it is determined that there is no possibility that the first inter-vehicle distance will extend to the length that allows for the lane change. a first inter-vehicle distance acquiring unit configured to acquire, in a position lateral to a vehicle on an adjacent lane adjacent to a lane on which the vehicle travels, a first inter-vehicle distance that serves as a target for a lane change of the vehicle and is an inter-vehicle distance between a first preceding adjacent vehicle in a lateral forward direction of the vehicle and a first subsequent adjacent vehicle in a lateral rearward direction of the vehicle; a second inter-vehicle distance acquiring unit configured to acquire a second inter-vehicle distance that is at least one inter-vehicle distance of an inter-vehicle distance between the first subsequent adjacent vehicle and a second subsequent adjacent vehicle as a vehicle subsequent to the first subsequent adjacent vehicle and an inter-vehicle distance between the first preceding adjacent vehicle and a second preceding adjacent vehicle as a vehicle preceding to the first preceding adjacent vehicle; a lane change possibility determining unit configured to determine a possibility of the lane change from the lane on which the vehicle travels to the adjacent lane by using the first inter-vehicle distance; the travel control device being characterized by a waiting necessity determining unit configured, when the lane change possibility determining unit determines that the lane change from the lane on which the vehicle travels to the adjacent lane is not executable, to determine presence or absence of a possibility that the first inter-vehicle distance will extend to a length that allows for the lane change by using the second inter-vehicle distance, to determine that waiting is necessary when it is determined that there is the possibility that the first inter-vehicle distance will extend to the length that allows for the lane change, and to determine that the waiting is unnecessary when it is determined that there is no possibility that the first inter-vehicle distance will extend to the length that allows for the lane change.