Road surfaces matter: the difference between rough and smooth pavement can be as much as five percent. Even more important is the architecture of the road. Quite often, our rout would divert us from a primary two-lane highway onto a back road or farm lane. Aside from the scenery, one of the greatest differences between these types of roads is the investment in leveling. Major highways feature cuts and fills that level the surface and create more even grades. Secondary roads are more likely to follow the ups and downs of the natural terrain. When driving a car, where the slight press of the gas pedal can maintain speed, one tends to miss the subtle ups and downs of a secondary road. When working with a single horsepower of driving force, these same roads require frequent gearing changes and some slow uphill crawls. After our summer tour, I'll go back to an automobile, the same as most Americans. When I do, it will be interesting to see if the hyper-mile skills perfected during the tour will stick and turn me into a more fuel efficient driver.