Hello Alan & Carole
Most Sat-Nav's offer a choice of vehicle when you set up the unit, but all this does is apply different speed profiles to the route - the route its self does not change so regardless of which model you choose they are all capable of stranding you up a dead end track.
As yet there is no automatic answer to overcome this shortcoming, but most of the units do give the option to avoid ferries, motorways, and or toll roads. - but this does not really help you.
Some offer a choice of shortest vs fastest. The fastest seems in most cases to use the major roads, so that is your best option.
The only guaranteed solution is to let the Sat-Nav plan your journey, then, you review it against a good map before you start the journey. You can then see from your map where there may be a problem, and then instruct the Sat-Nav to avoid that area by setting a 'via' point on the route you are happy with.
I personally use a model purchased from Aldi under the Medion brand name, and other members of my family use other models from Mio. None of them seem to know the routes I know around my locality, and they have taken what seems to be some strange routes into Birmingham and other areas that I visit.
So I normally have a fair idea of where I am heading, and the names of places I need to travel through, and the Sat Nav comes into its own in towns and cities where it does seem to be programmed with all the one way systems I have encountered.