When I started RVing, there was Microsoft Streets and Trips and DeLorme Street Atlas. Streets and Trips hasn't been updated in awhile. I suspect because Microsoft wants to sell you an updated version every year. But I still use it for initial planning. Not many new expressways since they stopped. Others swear by Street Atlas. I tried it but didn't like it. Probably because its hard to teach an old dog new tricks.
I do plan on downloading Good Sam's free trip router. I would think its more tuned into our hobby. We'll see.