Some people sent a convoy up the road consisting of about 50 trucks nose to tail, and these were pretty easy marks, as per this shot of a much earlier convoy in the vicinity (road to Binh Ba), shows;

A comforting sight!
The Australian way was to cut a convoy up into "packets" usually comprising 6 or so trucks (about a section). These "packets" came under the control of the packet commander, usually a Cpl or L/Cpl, (some times known as a sect commander. The different terminology comes about because whereas a Section Commander commanded a particular section within a Platoon, a packet may be made up of trucks from a number of different sections or even Units. Sounds insignificant, but there is a difference.)
Each vehicle in a packet would travel approx 100 yds between vehicles (So the numberplate was just readable) and each packet was separated even further apart. (See Commander's Diaries, convoy orders)
Each Packet was issued with at least one AR (Heavy barrelled automatic version of the SLR) or a GPMG M60, and had a radio set issued to the packet commander.
The idea of this spacing was that an ambush could realistically only knock out one or two trucks and the rest could take whatever avoiding procedure presented itself, whereas a closely packed convoy often suffered the fate of the photo as the attackers only had to knock out the first and last and the rest had nowhere to go.
Regards
Glen