Over the past few years, Vehicular Delay Tolerant Networks (VDTNs) have been exploited in those communications that do not take place through end-to-end connectivity. VDTNs framework is characterised by frequent disconnection, network partitioning, and high delay. A number of routing protocols have already been proposed for VDTN. These protocols make effort to achieve significant delivery potential with low network overhead. Geographic routing is an alternative. The protocols in geographic routing utilise the fact that most vehicles are equipped with Global Positioning System (GPS). The major concern of Geographical Routing Protocols (GRPs) is to enhance the delivery potential and to minimise the delay. This paper provides a comprehensive investigation of recently proposed GRPs. Additionally, open issues and future orientations are included in order to motivate the further research.