Driving down an interstate highway, like 1-44 as it passes Springfield on its way to Joplin, you can drive many a mile and hardly have to touch your steering wheel. In the 25 miles to Mt. Vernon, I-44 makes only two gentle curves. Of course, this is by design. The interstate highway system "ironed" out many of the curves and ups and downs that the older state and federal highways contained.
And this has had a positive effect on car and truck accidents, and the interstates are among the safest highways. However, nature, or at least human behavior, demonstrates that there is no free lunch. The price we pay for those long straightaways is the tendency of these often-monotonous stretches of road to lull a driver into a condition sometimes called "highway hypnosis."