A slipform paving machine apparatus, comprising: an apparatus frame including a main frame module and at least one laterally extendable side frame member (14, 16); at least one first side ground engaging unit (40A, 40C) and at least one second side ground engaging unit (40B, 40D); front and rear first side height adjustable supports (44A, 44C) supporting the apparatus frame from the at least one first side ground engaging unit; at least one second side height adjustable support (44B, 44D) supporting the apparatus frame from the at least one second side ground engaging unit; a variable width mold (52, 54) supported from the apparatus frame beneath the apparatus frame and laterally between the at least one first side ground engaging unit and the at least one second side ground engaging unit, the mold being configured to mold concrete into a concrete structure having an upper surface and lateral concrete sides as the apparatus moves forward in an operating direction; at least two three-dimensional stringless reference objects configured to correspond to positions of the objects relative to an external reference system; characterized in that the at least one laterally extendable side frame member (14, 16) is configured to be laterally extendable relative to the main frame module to vary a frame width on the fly as the apparatus moves forward in an operation direction; the variable width mold (52, 54) is configured to be variable in width so as to vary a paving width of the concrete structure on the fly as the apparatus moves forward in an operating direction; and the slipform paving machine apparatus comprises a carrier frame having the at least two 3D stringless reference objects (S1, S2) fixedly attached to the carrier frame so that a distance between the at least two 3D stringless reference objects is fixed, the carrier frame being supported from at least one of the main frame module and the at least one laterally movable side frame member (14, 16). an apparatus frame including a main frame module and at least one laterally extendable side frame member (14, 16); at least one first side ground engaging unit (40A, 40C) and at least one second side ground engaging unit (40B, 40D); front and rear first side height adjustable supports (44A, 44C) supporting the apparatus frame from the at least one first side ground engaging unit; at least one second side height adjustable support (44B, 44D) supporting the apparatus frame from the at least one second side ground engaging unit; a variable width mold (52, 54) supported from the apparatus frame beneath the apparatus frame and laterally between the at least one first side ground engaging unit and the at least one second side ground engaging unit, the mold being configured to mold concrete into a concrete structure having an upper surface and lateral concrete sides as the apparatus moves forward in an operating direction; at least two three-dimensional stringless reference objects configured to correspond to positions of the objects relative to an external reference system; characterized in that the at least one laterally extendable side frame member (14, 16) is configured to be laterally extendable relative to the main frame module to vary a frame width on the fly as the apparatus moves forward in an operation direction; the variable width mold (52, 54) is configured to be variable in width so as to vary a paving width of the concrete structure on the fly as the apparatus moves forward in an operating direction; and the slipform paving machine apparatus comprises a carrier frame having the at least two 3D stringless reference objects (S1, S2) fixedly attached to the carrier frame so that a distance between the at least two 3D stringless reference objects is fixed, the carrier frame being supported from at least one of the main frame module and the at least one laterally movable side frame member (14, 16).