Vehicular Ad hoc network(VANET) are special type of Mobile Adhoc Networks(MANET) where wireless equipped vehicles from a network are continuously travelling along the road. Node movement feature of Vehicular ad hoc network (VANET) closely resembles with that of mobile ad hoc network (MANET) but its high speed mobility and unpredictable movement characteristics are the key contrasting feature from that of MANET. The similarity nature suggests that the prevailing routing protocol of MANET is very much applicable to VANET. However, on the same line, the dissimilarity characteristics result in frequent loss of connectivity. In VANET, topology changes rapidly and there is frequent disconnection which makes it difficult to design an efficient routing protocol for routing data among vehicles called vehicle to vehicle communication. Many routing protocols where implemented like AODV, AOMDV, SD-AOMDV, DSDV, CBDRP. SD-AOMDV adds the speed and direction as two mobility parameter. By enhancing the performance of SD- AOMDV routing protocol, packet delivery ratio, and throughput can be increased and end-to-end delay can be reduce
