Everything Everywhere Daily: History, Science, Geography & More - The Interstate Highway System

Episode Date: July 29, 2020

After the end of WWII in Europe, General Dwight Eisenhower was appointed the military governor of the American Zone in Germany. During his travels around Germany, he noticed that the German autobahn was really good. His respect for the German highways later became the impetus for passing legislation for the United States Interstate Highway System. Learn more about your ad choices. Visit megaphone.fm/adchoices

At the end of World War II in Europe, General Dwight Eisenhower was appointed the military governor of the American zone in Germany. During his travels around Germany, he noticed that the German Autobahn was really good. His respect for the German highway later became the impetus for passing legislation for the United States' interstate highway system. Learn more about the road system which many people consider a greater American accomplishment than the Apollo program or the creation of the Internet. On this episode of Everything Everywhere Daily. What if your perceptions about the past were wrong? ThruLine is a podcast that takes you back in time to uncover the parts of the story that may have gone unnoticed. It effectively turned day into night and how it shaped the world now.

Time travel with us every week on the ThruLine podcast from NPR. This episode of Everything Everywhere Daily is sponsored by listeners like you. Creating a daily show like this isn't easy. researching, writing, and recording a daily show takes quite a bit of time, and you have to do it every single day. Over on patreon.com, there is a small but growing community of listeners who support the show with their donations. In addition to showing your support for the show, you can also get some extra benefits as well. Depending on your level of sponsorship, you can be listed as an associate or executive producer of the show. There's monthly original wallpapers for your desktop and smartphone, as well as merchandise like stickers, t-shirts, and hoodies.

Depending on your sponsorship level, you can also submit ideas directly to me, because this is a daily show and I need a lot of show ideas. Next month, patrons will also be able to get monthly ebooks of the episode transcripts as part of their support. As new projects, products, and events roll out over the next several months, patrons will have first dibs on everything. If you would like to be a sponsor, go to patreon.com slash everything everywhere, or click on the link in the show notes. By the mid-1950s, the automobile had been around for about 50 years. Car ownership rates skyrocketed after World War II, and with hundreds of thousands of soldiers returning home after the war and starting families, demand for road travel exploded. By 1956, it was possible to travel from coast to coast by car, but it wasn't easy. The highway system in the United States was a patchwork of state roads with varying degrees of quality.

The first transcontinental road across the U.S. was the Lincoln Highway, which went from Times Square in New York to Lincoln Park in San Francisco. Established in 1913, the road was a private endeavor, which mostly was just a route that connected already existing roads. Almost nothing on the Lincoln Highway was paved and getting stuck in the mud was a very common occurrence. In 1919, the U.S. Army sent a transcontinental convoy from Washington, D.C. to San Francisco to demonstrate the need for better roads in the country. On that convoy was a young major Dwight Eisenhower, who traveled with the convoy, which averaged a speedy five miles an hour during the trip. By the 1920s, routes like the Lincoln Highway were replaced by the United States numbered highway system.

This was a system of numbered roads that was coordinated between the states, but the federal government had nothing to do with the system. It was and still is managed by the American Association of State Highway and Transportation officials. All of the roads are built and maintained by state and local governments, and the only coordination between the states is regarding the numbering system. It was this system that gave us such famous roads as Route 66, which went from Chicago to Santa Monica, California. When Eisenhower became president in 1953, the national highway system was a disjointed collection of roads of varying standards and levels of quality. In his presidential memoirs, he noted, during World War II, I had seen the superlative system of German Autobahn and the national highway system crossing that country.

He wanted a similar system for the United States. There had been plans kicking around for almost 20 years for such a system, but the war had gotten in the way of doing anything. In 1954, he appointed Lieutenant General Lucius Clay, his right-hand man who oversaw the logistical operations of the Normandy invasion, to head up the President's Advisory Committee on the National Highway System. The Clay Commission developed a grand plan, which is a $100 billion, 10-year program,

to connect the country with a network of 40,000 miles, of divided highways connecting every city with a population of at least 50,000 people at the time. Congress passed the Federal Aid Highway Act of 1956, which was signed by President Eisenhower in June. Construction of the first segments of the system was begun in August of that year in Missouri. One of the major rationales for the program was National Defense. In fact, the official name of the system is the Dwight D. Eisenhower National System of Interstate and Defense Highways. Defense was baked into the system from the beginning. There were several arguments put forward as to why the interstate system was needed for defense.

The first and biggest reason was legal. Nowhere in the Constitution does it stipulate the federal government can establish a system of roads. Using defense as the excuse provided legal cover for the project. Second, there needed to be a way to move troops and equipment across the country quickly should the need arise. Third, as it was the middle of the Cold War, the interstate system, system was thought to be a way people could quickly evacuate major cities in the event of a nuclear attack. Finally, the system was designed to allow aircraft to use the roads as runways for takeoff and landings. This actually has never happened other than in the case of an emergency, but it is

possible that some straight remote stretches of interest state could be used as a runway in a pinch. There are several standards which define the interstate system, and that will be found on every interstate highway. The first is controlled access. The only way on or off any interstate road is via an on or off ramp. You can't make a right or left-hand turn anywhere to get on the road. There are no stop signs or traffic lights anywhere on the road, except in the case of construction. There are no crossroads. Any road which crosses an interstate must go over it or under it. Likewise, there are no train tracks across the interstate at any point. All segments of the interstate system have at least four lanes with two

in each direction. Each side of the road is separated by a median of at least 50 feet in rural areas and 10 feet with a concrete wall in urban areas. Each lane must be a minimum of 12 feet or 3.7 meters. The maximum allowable grade is 6%. The left paved shoulder must be at least 4 feet, and the right paved shoulder must be at least 10 feet, except for bridges over 200 feet and tunnels, which may have a 4-foot shoulder. The minimum clearance for any bridge or tunnel is 16. feet. Road should be designed for a minimum speed of 70 miles per hour or 113 kilometers per hour. There are a small number of exceptions to these rules due to roads being grandfathered in. For example, the Mackinac-Abridge connecting the upper and lower peninsulas of Michigan has no median

because it was built before the system started. The numbering of the interstate highway system is very particular and purposeful. All routes which generally go north-south are odd-numbered. One example is Interstate 35, which goes from Laredo, Texas. to Duluth, Minnesota. All routes which generally go east-west are even-numbered. Interstate 90 goes from Boston to Seattle. Numbers for odd-numbered roads generally are lower in the western U.S. and get higher as you go east. Interstate 5 goes from San Diego to Everett, Washington. Interstate 95 goes from Miami to the Canadian border in Maine. Numbers for even-numbered roads are lower in the south and higher in the north. Interstate 4 crosses Florida from Tampa to Daytona Beach, Interstate 94 runs from Detroit to Billings, Montana.

This system is the exact opposite of how state highways are numbered. The Pacific Coast Highway is 101, and the highway which ends in Key West Florida is Highway 1. This was done so no state had two highways with the same number to avoid confusion. There are some minor exceptions to the numbering system as new roads are built, but generally the rule holds. The highest speed limit on the system is in Texas at 85 miles per hour, although there was no speed limit at all in Montana between 1995 and 1999. The lowest speed limit on the interstate system is Interstate 35E in St. Paul, Minnesota, which has a very brief stretch that is 45 miles per hour. The longest road is the previously mentioned Interstate 90, which is 3,020 miles long, and the

shortest is Interstate 87 in North Carolina, which is only 13 miles long. That's not including spur segments. The widest section of the interstate is Interstate 10, just outside of Houston, Texas, which has 26 lanes. Speaking of spur segments, belts and spurs have their own numbering system. If an interstate road has three digits, that means it is a spur or bypass highway. If the first digit is even, then it's a bypass or beltway road, and the last two digits are the main interstate road it connects to. For example, in the Twin Cities, the road which bypasses to the north is 694, and the one to the south is 494. If the first digit is odd, then it's a spur road that only connects to the highway at one end.

Using the same example, Interstate 394 goes into downtown Minneapolis and connects with Interstate 694 in the western suburbs. Despite the name Interstate, Alaska, Hawaii, and Puerto Rico all have interstate highways, even though they don't connect to another state. state. Their roads are all named with an initial before the road number, H for Hawaii, A for Alaska, and PR for Puerto Rico. Each state can set up its own system of exits. California was the only state with no exit numbers, but they began numbering them in 2002 when they started replacing road signs. Most states number exit based on mile markers, except for the northeastern states where the exits are numbered sequentially. Exits and mile markers usually begin at the southern or westernmost state line.

The initial plan for the interstate highway system was declared finished in 1992, and today there are 48,191 miles of road which the system covers. I'll end this trip down the interstate highway system with one final note. The entire system, as you would guess, is measured in miles, except for one single road, which is metric. Interstate 19, from Nogales to Tucson, Arizona, has everything. measured in kilometers. The original signs were put up in the 1970s when everyone thought the U.S. was going to be moving to the metric system, but it just never happened. In 2004, there was a plan

to eventually replace all the metric references to miles, but then business people objected because it would require renaming all the exit numbers and the businesses didn't want to spend money to change their directions. As of this year, and I know this because I drove the highway just this January, all the signs on I-19 are still in kilometers. Executive producer of Everything Everywhere Daily is James Mackala. Special thanks to everyone who supports the show over on Patreon. Please remember to leave a review over on Apple Podcasts. Even a simple review can really help the show get discovered in the sea of other podcasts that are out there.