yes there is a setup as with any electronic device. truck height and weight. hazmat or non-hazmat. number of axles. many variables that have to be programmed into the unit to keep you routed where you're supposed to be.....but even then it still sometimes blows it and tries to route you somewhere you shouldn't be. you have to know these things. it's called good trip planning.
truck specific GPS will route you based on parameters you enter such as length weight and height they all also have points of interest (POI) that tell you of fuel stops and weigh stations along your route I use google earth to get the birds eye view of shippers and recievers many times your bills will have the address of the office truck entrance might be on a different street around back a block or better away
Yours too? Well glad I'm not the only one. I just switch to car mode cause usually all I'm using it for is knowing how many miles left.