A roof cargo box system for transporting an article on a vehicle includes a roof cargo box and a roof cargo box carrier for mounting on a vehicle. The box includes a flexible shell for accommodating the article to be transported. The roof cargo box defines a longitudinal axis and has at least three frames which extend in respective planes transversely to the longitudinal axis. The frames are configured to receive the flexible shells spanned thereon. A scissors mechanism pulls the frames into a predetermined spaced relationship to each other along the longitudinal axis. The carrier for mounting a roof cargo box on the vehicle includes a first attachment unit for mounting on the vehicle and a second attachment unit for attachment to the roof cargo box. The roof cargo box carrier also includes a separable mechanism for rotating the attachment units relative to each other by at least 90°.