Traffic routing guidance algorithms which only consider user satisfaction will result in road density unbalance. On the contrary, the route algorithms will not meet user request if they merely focus on the traffic load balance. So it is important to take user satisfaction and traffic load into consideration at the same time. Although a few works focus on this combination, they ignore the difference between the user requests. We propose a traffic dispersion routing algorithm on VANET naming BPR-US which is based on backpressure theory. It tries to satisfy the user demand and also separates the traffic flow. At last, we make simulation experiments to compare BPR-US algorithm and other route guidance algorithms, proving that BPR-US algorithm can have a better effect on both user satisfaction and traffic load.