Systems, methods, and software for managing radio resources for vehicle-to-vehicle (V2V) communications. A geographic area is segmented into zones with a subset of the transmission slots allocated to each of the zones. The subset of the transmission slots allocated to each zone is partitioned into periodic transmission slots assignable to individual vehicles for periodic transmissions and special transmission slots reserved for special transmissions according to a contention-based protocol. A resource manager stores a mapping of transmission slots for each of the zones. When a vehicle enters one of the zones, the resource manager performs a slot assignment for the vehicle from the periodic transmission slots allocated to the zone, and transmits a notification to the vehicle indicating the slot assignment.