hi dennis
i bought a tomtom satnav that had the truck version installed on to it.
having had two other satnavs before, a navman and a navigon - i have found this one the best.
if your driving solo and put in the destination it will send you one way, but change it to truck and it will stick to motorways and main roads.
we are going away at the weekend to a site at selby, if i say i'm in a car it's 29 miles, the same destination but for a truck 32 miles - both the navman and the navigon no matter how i set them up would still take me down little country roads with the caravan on tow, but on a reasent 800 mile tour it always kept to the main roads.
always check the rout before you set off with a good upto date map and you should have no problems