The vehicles are connected through the internet in the vehicular Adhoc network environment. When any emergency vehicle like an ambulance arrives, we have to create a green corridor to that ambulance so that it will reach safely. The communication between the ambulance and the other entity like RSU or other vehicles through the open channel, These open channels are the main target by the adversary to get the messages which will transfer between two entities. The adversary will modify, delete or eavesdrop on the message to do the attacks like privileged-insider attack, replay attack, man in the middle attack or other related attacks. In this paper, we will propose the new TCPPA authentication protocol to secure the intelligent transportation system in a vehicular network. We also analyzed the security features in informal security analysis. A formal security analysis is done using the BAN logic. Additionally, we employ the ROR model for mathematical proof and the AVISPA simulation tool for security analysis. At last, an exhaustive comparative analysis will be conducted between the proposed work with some other existing works.