don't send a truck to export/import if it is jsut going to sit there waiting for other trucks
add a limit to either the number of vehicles or the current queue of vehicles against the time it takes to get there. waiting for a load or 2 is one thing but as of right now the system will often send every spare truck truck to a new job. and they all just sit there trapped waiting for the truck in front of them to load while other jobs get ignored.