Totally OT: I'll check next time I use the Nuvi, but at least some Garmin GPS receivers have a preferences option where you can specify highways, back roads, shorter time vs shorter distance, et al... It might be under tools, but if your unit only shows you the interstate, somewhere there's a file telling it to ignore back roads. Heck, my first Nuvi routed me off I-5 in Tacoma through city streets and back onto I-5 to avoid traffic. I was still in traffic but probably saved a bit of time.