Vehicular Ad hoc Networks (VANET) are expected to have great potential to improve both traffic safety and comfort in the future. When many vehicles want to access data through roadside unit, data scheduling become an important issue. In this paper, we identify some challenges in roadside based data access. To address these challenges we first review some existing scheduling schemes. We then propose a priority scheduling and finally show that using this idea can increase QOS compare to previous algorithms. KEYWORDS VANET, V2V , V2I , RSU , Packet scheduling