Driving on active logging roads can be hazardous. They're narrow, unpaved, and
usually have no shoulder or guardrails. Bridges are invariably only wide enough for
one vehicle. They are frequented by logging trucks, which are large and when loaded,
heavy vehicles. A loaded logging truck carries anywhere from 45 to 100 cubic metres of wood. One cubic metre of spruce weighs about 450 kilograms. People familiar with logging roads know that the first rule of the road is:
Because of the hazards of driving on active logging roads, it is desirable for people on such roads to be able to communicate with each other and announce their positions. If, for instance, you are approaching a bridge from the burdened side, if you know that there is a truck coming toward you, you will pull over and let the truck by. In Canada (possibly elsewhere, but this is where my own experience is from), vehicles travelling on logging roads are supposed to be equipped with radios. Each road is assigned a frequency, which is posted at the entrance to the road. When you enter a road, you set your radio to the assigned frequency and monitor the traffic. This lets you know what other people are doing and where they are. You also announce your position periodically, typically every few kilometres. At critical points, such as the approach to a bridge, you are required to announce your position. In addition to the mileposts placed every kilometre along the road (they're still called mileposts even though Canada is on the metric system, another instance of etymology not determining meaning.) there are special posts at critical points so you can announce exactly where you are.
There is a specialized vocabulary for announcing one's position. A typical announcement
will be something like this:
Whether or not a vehicle is actually loaded is sometimes of interest to other people.
A heavy truck, for instance, needs to be given more leeway when it is loaded than
when it is unloaded. So, if your vehicle is not in the canonical state for its
direction of travel, you may indicate this. For instance, if you are driving a
truck carrying equipment out to a work site, you may announce:
There is one exception to the use of loaded and unloaded to indicate direction. Sometimes two different logging roads are close enough to be within radio range. In this case, announcements may contain the name of the road as well as the position, but often one road is assigned the terms loaded and unloaded and the other is assigned the terms empty and with a load. This will be indicated on the sign at the beginning of the road along with the radio frequency to use. This makes it unnecessary to name the road.
Ideally every vehicle on an active logging road has a radio, but in practice some don't. Someone without a radio is said to be driving blind. Different roads have different cultures. On some roads, people are cooperative and look out for each other. If there are vehicles without radios, people with radios will announce their location. Other roads lack this sense of community.
Of course, logging truck radios are also used for gossip and emergency communications. In some areas, they are a good place to hear conversations in native languages.
Here's a picture of my truck, showing its three antennae. One is for the usual
commercial broadcast band, one for the CB, and one for the logging road radio.
It is parked at my friends' house at Tsetl'oni'a, on Tachek Lake, outside
of Vanderhoof, British Columbia. My canoe winters down by the shore.