A rapidly detachable switch device for children's vehicles, including a handle assembly that selectively effects switching between plural scooter vehicle configurations, from a fixed-spread sporter configuration to a free-swinging flicker configuration, from the flicker configuration to a fixed scooter configuration, and back from the flicker configuration to the sporter configuration by moving a switch lever member between rearwardly lowered and near-vertically raised positions. The various configurations can be selected rapidly, realizing a three-in-one function for vehicles that can be switched by a rider of the vehicle, the lever being pivotally included in a conveniently removable handle lever assembly.