In Vehicle-to-Infrastructure (V2I) communications, the broadcast data towards the vehicles must use the network resources efficiently while the unicast data must arrive reliably with ultra-low-latency. Furthermore, the connections must remain network-attached while vehicles move rapidly. A system/method are described through which a vehicle with a special communications module and internal computer can connect to one or more 5G vehicular network slices (VNS) with multiple Radio Access Technologies (multi-RAT) in order to efficiently communicate with local or remote transportation information databases and applications, road safety and emergency infrastructures. The infrastructure of this disclosure uses the network-slicing feature of a 5G mobile network to carve out a vehicular data and control planes specialized to offer the vehicular service only. The vehicular network slice further comprises (i) Road Side Access Unit (RSAU), (ii) Vehicle Id registrar (VIR), (iii) Vehicular Slice Manager (VSM), and (iv) distributed Virtual Transportation Network Functions (VTNF).