Abstract: Each transport device contains at least two drive wheels which are driven at individual speeds V.sub.A and V.sub.B and which are pivotable by related steering angles .alpha. and .beta.. Identical servo-drive units are associated with the drive wheels and their mode of operation and mutual coupling is adapted by switch devices to the steering angles .alpha. and .beta. such that the required speed adjustment must not be computed in accordance with the relationship V.sub.B =(cos.alpha./cos.beta.). V.sub.A but the speed is automatically adjusted through the entire steering angle range of -90.degree. to +90.degree.. At .alpha.=.beta.=0.degree. the leading servo-drive unit is rigidly guided by its speed regulation loop as a MASTER servo-drive unit and its armature current is supplied as a reference magnitude to the armature current regulation loop of the trailing servo-drive unit which is operated as a SLAVE servo-drive unit. At .alpha.=.beta.=.+-.90.degree.