While I was investigating if any laws existed pertaining to how long “Old Exit” signs should remain in service, I stumbled upon this list of answers by the Federal Highway Administration of the United States to questions which are frequently asked pertaining to Interstate highways.
States Own Interstate Highways — Not the Federal Government — and Other Fun Facts
One key to the answer to the “Old Exit” signs question is that “The States own and operate the Interstate highways.” The only exception is the Woodrow Wilson Memorial Bridge, which is currently under construction and spans Interstate 95 and Interstate 495 over the Potomac River; but once the old bridge is replaced, that ownership will be reverted to the states of Maryland, and Virginia — as well as the District of Columbia — all of which operate the bridge.
I have heard that Interstate highways were constructed for the purpose of having airplanes land in times of national crises — specifically, one of five miles of Interstate highway must be straight for this purpose — but that “is a myth that is so widespread that it is difficult to dispel” as “no legislation, regulation, or policy has ever imposed such a requirement. Airplanes do sometimes land on Interstates in an emergency, but the highways are not designed for that purpose.”
Did you know that the Interstate system of highways is 46,876 miles in length and was constructed at an estimated total cost of $128.9 billion? Did you also know that there never was a national speed limit of 55 miles per hour, as speed limits were determined by individual states?
You can also find out the answers to such questions as why Interstate 50 does not exist; who designed the Interstate shield; how states can charge tolls on highways which tax dollars are used to build; why some highways are numbered out of sequence and why they are not always corrected.
Summary
I will throw in one of many tidbits of trivia pertaining to Interstate highways in the United States which are not part of the aforementioned list: did you know that Interstate 19 in Arizona uses the metric system in terms of distance? Even the numbering of exits is denoted in kilometers.
I have always been fascinated with highways and maps; and I truly enjoy road trips — so as usual, I welcome your thoughts and trivia as well.
All photographs ©2017 by Brian Cohen.