Accidents have been a serious issue of all times. VANET is an emerging mobile adhoc network used in order to improve vehicle and road safety, traffic efficiency, and convenienceas well as comfort to both drivers and passengers. But in VANET, in sparsely populated areas, the messages are not propagated to the neighbors properly, due to fading of messages with distance.There are several solutions to this issue. A Vehicle to Vehicle(V2V) based gossip network may prove effective but if a gossip dies out then it is not fruitful. A V2V store-carry-forward mode of information transfer may be used, but again the results are not guaranteed. The proposed system provides an overview about issues with V2V communication and existing solutions in sparsely populated areas, and points to usage of hybrid model with minimal V2V or no V2V for sparsely populated areas which uses Vehicle to Road side unit(V2R) or Vehicle- to – infrastructure(V2I) which uses existing infrastructure laid for mobile communication and needs very less add-on installations hence proves to be a cost effective solution.

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A Road Accident Prevention (RAP) scheme based on Vehicular Backbone Network (VBN) structure is proposed in this paper for Vehicular Ad-hoc Network (VANET). The RAP scheme attempts to prevent vehicles from highway road traffic accidents and thereby reduces death and injury rates. Once the possibility of an emergency situation (i.e. an acci-dent) is predicted in advance, instantly RAP initiates a highway road traffic accident preven-tion scheme. The RAP scheme constitutes the following activities: (i) the Road Side Unit (RSU) constructs a Prediction Report (PR) based on the status of the vehicles and traffic in the highway roads, (ii) the RSU generates an Emergency Warning Message (EWM) based on an abnormal PR, (iii) the RSU forms a VBN structure and (iv) the RSU disseminates the EWM to the vehicles that holds the high Risk Factor (RF) and travels in High Risk Zone (HRZ). These vehicles might reside either within the RSU’s coverage area or outside RSU’s coverage area (reached using VBN structure). The RAP scheme improves the performance of EWM dissemination in terms of increase in notification and decrease in end-to-end delay. The RAP scheme also reduces infrastructure cost (number of RSUs) by formulating and deploying the VBN structure. The RAP scheme with VBN structure improves notification by 19 percent and end-to-end delay by 14.38 percent for a vehicle density of 160 vehicles. It is also proved from the simulation experiment that the performance of RAP scheme is promis-ing in 4-lane highway roads.