I know that KLLM uses them and its a way for OTR drivers to drive to a city where their load is scheduled to delivered and upon the permission given from the DM the driver can drop the load and grab another and get back on the interstate going to a different city. Then someone else becomes responsible for the load, maybe a local driver?
I think it's a great idea. Let the OTR drivers haul between states/cites then let the hourly guys haul to the receivers sit parked waiting to be unloaded for an hourly wage. Everyone is happy.