Abstract :
VANET are becoming active area of research and devel- opment because it has potential to increase road safety, convenience and comfort to drivers & passengers. A Lot of research work on VANET have done in area of Quality of Service (QoS), routing and security. These concepts relate the facing challenges for technology in VANET. We present a overview of challenges in VANET. Firstly ,we have discussed about VANET technology and routing methods. The aspects related to security have explored with challenges related to threats. Further there is discus- sion about Quality of Service, routing and technical issues as well as social and economic challenges.