We consider a tactical command center that issues broadcast data message flows for dissemination to all vehicles traveling as team members of a convoy, or along a multilane linear road segment. We propose a networking protocol which uses location aware data to identify and elect certain vehicles that reside at preferred locations to act as relay nodes, forming a dynamic multi-hop backbone network. The presented mechanism, identified as a Vehicular Backbone Network (VBN), optimally sets the rate of the adaptive coding scheme for the backbone links, while jointly configuring the targeted inter-relay distances and the proper reuse level for a reuse-M spatial-TDMA medium access control (MAC) scheme. We present a fast and efficient mechanism for the dynamic and spatially distributed implementation of the backbone-node election process. For this purpose, we make use of the spatial structure governing the mobility of vehicles across a multi-lane linear highway. To assure the robustness of the election scheme, we assume the backbone synthesis process to be performed at a Forwarding Layer, above the MAC layer, and thus be transparent to the character and operation of the employed (whether contention-less or contention oriented) MAC layer protocol. We present a mathematical model for the determination of the VBN system's parameters that serve to produce the highest throughput capacity rate.