- ... that the passing lanes of the Arroyo Seco Parkway (pictured), California's first freeway, were paved in a different color to encourage drivers to stay in their lanes?
- ... that Henry Ford helped stop construction of a state highway in the Upper Peninsula of Michigan in order to gain admission to the exclusive Huron Mountain Club?
- ... that New Mexico State Road 4 forms the core of Jemez Mountain Trail National Scenic Byway, with trails to Puebloan ruins, a 10,199-foot (3,109 m) mountain, and a 70-foot (21 m) waterfall from roadside turnouts?
- ... that Nevada State Route 88 is one of three state routes that cross the Nevada-California state line with the same number?
- ...that Interstate 270 Spur in Maryland is the only Interstate Highways to have the word "Spur" next to the I-270 shield?