Synthetic molecular motors can be fuelled by the hydrolysis(1-4) or hybridization(5-11) of DNA. Such motors can move autonomously(1-4,7,11) and programmably(12), and long-range transport has been observed on linear tracks(13,14). It has also been shown that DNA systems can compute(8,15-18). Here, we report a synthetic DNA-based system that integrates long-range transport and information processing. We show that the path of a motor through a network of tracks containing four possible routes can be programmed using instructions that are added externally or carried by the motor itself. When external control is used we find that 87% of the motors follow the correct path, and when internal control is used 71% of the motors follow the correct path. Programmable motion will allow the development of computing networks, molecular systems that can sort and process cargoes according to instructions that they carry, and assembly lines(19,20) that can be reconfigured dynamically in response to changing demands.