I have the Garmin 24K Topo map installed on my Oregon 300 and I was checking out how the automotive profile worked. My visual pointer kept pointing in various directions as I was driving on NF Roads. It also showed that I was "off" the dirt road as well. As far as on highways, occasionally it would show me driving off the side of the highway but would later show the icon correctly on the highway. I know the 24K Topo is not for highway driving but it did show the highway I was on. Doesn't bother me too much as I use it for off-highway use and hiking. Just a side note, my Nuvi 255W with City Navigator performed excellent in regards to showing the NF roads. It indicated each dirt road and the FS road number.