A method is provided for delivering data messages in an inter-vehicle ad hoc network. The inter-vehicle ad hoc network utilizes a multi-hop routing protocol for storing, carrying forward and distributing a data message to various vehicles traveling along the road. The method includes determining a first cluster consisting of a group of vehicles proximate to one another traversing along a road in a first direction. A determination is made as to which vehicles within the first cluster are trailer vehicles for re-broadcasting messages based on vehicle position within the first cluster. An event is detected in a travel path of the first cluster by one of the vehicles in the first cluster. The event is reported to other vehicles in the cluster. At least one vehicle in a second cluster moving in an opposite direction to the first cluster is detected. The data message is broadcast from the determined trailer vehicles to the second cluster.