I am planning a trip this July from Milwaukee to San Francisco. It is not a pleasure trip, I am looking to minimize time on the road. The truck I am driving is older and I would like to take the route that avoids the steepest and most difficult roads (elevations changes). So the ideal route will be a combination of shortest distance with the least amount of mountain driving and elevation changes.
Should I take 90, 80 70? Or some other road. I don't want to drive all the way south to 10.