In vehicular Ad-hoc Network (VANET) a restricted coverage of Wi-Fi and extremely mobile nodes creates the topology vigorously changing and repeatedly disconnecting. Subsequently Quality of Service turn out to be an essential issue. In this work, we acknowledged the need of Quality of Service restraint in VANET [3]. Investigation related to work signifies that, an effective routing methodology plays a vital role, to upturn the Quality of Service parameters. To handle this Ant Colony Optimization (ACO) and been applied, and to carry out the experiment Opportunistic Network Environment (ONE) Simulator is being used to study about packet drop, overhead ratio, average latency and throughput. We studied mainly four performance metrics (overhead ratio, average latency packets dropped and the throughput) signs that our proposed approach is more effective and trustworthy in comparison of existing routing algorithm. The target of refining the QoS in these systems is done utilizing ONE test system. A meta-heuristic calculation, Ant Colony Optimization (ACO) is connected to acquire directing set-up and the reproduction is completed in ONE test system. To create the simulation more representative a genuine city plots with the simulator has been integrated [3].