There is a highway that wraps around a large lake, making a 90-degree turn through a gradual curve which follows the arc of a perfect circle. Each direction has 5 lanes for traffic, each of which is 12 feet (about 4 meters) wide, and the radius of the circular arc is about 8 miles (about 13 kilometers). What is the difference between the distance traveled along the circular arc if you drive in the leftmost lane in a single direction, versus the rightmost lane in that direction?
