Starting in 1923, markers were constructed—large, several dozen-foot concrete arrows covered with bright yellow paint, visible from a great distance, even from an altitude of 10 miles. At the ...

1,550 beacons stretched across 18,000 miles. Maintaining this system of giant concrete arrows cost $28 million a year (adjusted for inflation). Before the highway of light it took 83 hours to get ...

Starting in 1923, markers were constructed – large, several-metre-long concrete arrows coated with bright yellow paint, visible from a substantial distance, even from an altitude of 10 miles. At ...