A closed loop toy track system for a toy vehicle to move therein and along, comprising: a toy vehicle, and a plurality of tube sections (3, 10, 20, 40, 41) forming a closed loop track; the tube sections including at least first and second tube sections which are connectable endwise together to form part of the closed loop toy track; each of the tube sections having first and second parts which are connected with adjacent first or second parts of axially adjacent tube sections to axially connect the first and second tube sections; and interlocking structures which are provided on the first and second tube sections respectively and are connected with each other to fix the first and second tube sections whereby the tube sections are relatively rotatable about each other along a longitudinal axis running through each tube section, wherein the first and second tube sections are connectable endwise for inter-engagement to axially connect the first and second tube sections, including a connector formation (6, 7) in the end area of each tube section, the connector formation being for interlocking the adjacent tube sections and wherein the connector formations are mating elements including an interengaging flexible snap joint on a first tube for matingly engaging with a notched ring segment on a second tube, one of the flexible snap joint or notched ring segment extending around less than the entire circumference of its respective tube, and the other of the snap joint or ring segment extending around the entire circumference of its respective tube, such that relative rotation of adjoining tubes is possible over the entire circumference of the tubes; and wherein there are multiple tubes connected together to form the closed loop track, and the relative rotatable sections permit the track to be formed in a three dimensional layout; and wherein the toy vehicle is for frictionally engaging an inner wall of the tube under the biasing action of a spring in the vehicle urging the vehicle against the inner wall, and the toy vehicle includes a driving wheel mounted to be urged towards an inner surface of a tube of the track system to maintain frictional engagement of the driving wheel on the surface, a motor for rotating the driving wheel and gears for transmitting drive from the motor to the driving wheel, the toy vehicle being propelled through the tube collectively by the motor, and by the frictional engaging interaction of the toy vehicle with the inner wall of the tube, whereby the toy vehicle is propelled through the closed loop track, wherein each of the two tube sections is open ended with a substantially equal opening at both ends and throughout the tube thereby to be an unobstructed axial pathway from end to end whereby the vehicle can pass from end to end of the tube without obstruction and formed by two elongated portions, and each portion being a semicircular half tube (1, 2, 4, 5, 42, 43) having elongated edges, the semicircular half tubes being releasably connectable on the elongated edges thereby to form a circular open-ended tube, and the two elongated portions are separable from each other when in a released position relative to each other thereby to constitute two separated portions. at least first and second tube sections which are connectable endwise together to form part of the closed loop toy track; each of the tube sections having first and second parts which are connected with adjacent first or second parts of axially adjacent tube sections to axially connect the first and second tube sections; and interlocking structures which are provided on the first and second tube sections respectively and are connected with each other to fix the first and second tube sections whereby the tube sections are relatively rotatable about each other along a longitudinal axis running through each tube section, wherein the first and second tube sections are connectable endwise for inter-engagement to axially connect the first and second tube sections, including a connector formation (6, 7) in the end area of each tube section, the connector formation being for interlocking the adjacent tube sections and wherein the connector formations are mating elements including an interengaging flexible snap joint on a first tube for matingly engaging with a notched ring segment on a second tube, one of the flexible snap joint or notched ring segment extending around less than the entire circumference of its respective tube, and the other of the snap joint or ring segment extending around the entire circumference of its respective tube, such that relative rotation of adjoining tubes is possible over the entire circumference of the tubes; and wherein there are multiple tubes connected together to form the closed loop track, and the relative rotatable sections permit the track to be formed in a three dimensional layout; and