Nowadays, the rapid advances in wireless communications, positioning techniques and mobile devices enable location based service such as dynamic traffic navigation. Yet, it is a challenge due to the highly variable traffic state and the requirement of fast, on-line computations. This motivates us to design an intelligent city traffic control system, which is based on an extension of the Quad-tree access method that adapts better to the road networks while it maintains aggregated information on traffic density according to hierarchy levels. Based on this index, a view-based hierarchy search method is proposed to accelerate the optimal path computation. At the end, the experiment will show this index structure to be effective and efficient.