In the past decade, the networking and automobile industry has experienced the emergence of vehicular networks which were developed under the Intelligent Transportation Systems (ITS) to provide a plethora of safety and non-safety related applications. The provision of seamless mobility and session continuity is one of the major challenges for the transmission of ITS applications in vehicular networks. This is more critical when a communicating node moves from one subnet to another, a process referred to as inter-subnet handover. In such a case, we deal with the problem of fast and seamless handover support for better Quality of Service (QoS) provisioning especially, for throughputsensitive and delay-intolerant ITS applications. In this paper, we propose a scheme aimed at improving the handover performance in IP-based vehicular networks by maximising the correct handover probability (P Correct ) and increasing the data throughput during inter-subnet handovers. We demonstrate the impact of mobile node's speed and direction of motion on both P Correct and data throughput via numerical analysis.