FWIW, I replaced my Navigon dedicated unit with Co-Pilot Caravan Android app, which the software house then 'upgraded' to Co-Pilot GPS with motorhome/caravan options enabled. I've entered my motorhome length, width and height and (unlike the Navigon) it's not tried sending me under any height restriction so far. In general, it selects appropriate routes where a choice is available but will send me down narrow, single-track roads where there is a massive distance penalty to avoiding them or there is no other viable route. TBH, I thought that all half decent sat navs worked that way...