Recent year’s development in communication technologies have been able to deploy a whole new range of ad hoc networks of moving vehicles namely Vehicular Ad hoc Network (VANET). The key component of Intelligent Transportation Systems (ITS) is VANET only. The Vehicular communication systems is one of the critical complex infrastructure system of any nation. Thus, reliability i.e. having a low failure probability of such critical systems is the main concern of the academia and the industry. This paper primarily focuses on the reliability modelling of VANET. The main objective of the research is to address the issue of quantifying the importance of components in contributing to the reliability and maintenance of a VANET. Reliability Block diagrams (RBD)s have been modelled for the architecture of VANET. Out of various Component Importance Measures (CIM)s available in literature, Birnbaum measure, Improvement measure and Criticality Importance measures have been used to prioritize the system components. The research work is successful in identifying the most critical and the least critical component of the Vehicular Ad Hoc Network and thus provides a solution for the design improvement, maintenance and failure diagnosis.

Vehicular Ad hoc network is the most fast growing which shape fresh  engineering opportunities like controlling traffic smartly, optimal resource maintenance and improved service for customers. Vehicular Ad hoc Network (VANET) is one of the most popular ad hoc networks. A vehicular ad hoc network generally faces the problems like trust modeling, congestion, and battery optimization issues. If the nodes are comparatively less than it can handle the traffic well when it comes to transferring the data at a rapid rate. But, when it comes to high-density traffic than a Vehicular network always faces congestion problem. This paper tried to find the reliable solution to the traffic management by adding up the virtual gears into the network and optimizes the congestion problem by using a trust queue which is updated with the broadcast concept of the hello packets in order to remove the unwanted nodes in the list. The network performance has been measured with QOS Parameters like delay, throughput, and other parameters to prove the authentication of the research.