US Interstate Highways
Hi and welcome to Failurology; a podcast about engineering failures. I’m your host, Nicole
And I’m Brian. And we’re both from Calgary, AB.
This week in engineering news, NASA’s Perseverance Mars rover cored and stored the first sample of the mission’s newest science campaign on Thursday, March 30th in the Jezero Crater Delta on Mars. .
Perseverance collected 19 samples and 3 witness tubes in the crater and recently deposited 10 tubes as a backup cache on the Martian surface as part of the NASA-ESA Mars Sample Return Campaign.
Samples will be used to search for signs of ancient microbial life and to better understand the water cycle that has shaped the surface and interior of Mars.
Samples were collected from a diverse range of geology throughout the Jezero Crater.
Core samples were taken from a rock that has been named “Berea” that the team believes was formed from rock deposits that were carried downstream by an ancient river. As the material was carried downstream, this essentially allows 2 for 1 sampling (bonus sampling?) for an area beyond the Jezero Crater without having to physically travel to the location.
If you want to read more about the rover check out the link on the web page for this episode at failurology.ca
Now on to this week’s engineering failure; the US Interstate Highway System!
We have been doing odd failures in the #5 spots, and this episode, number 75 is no different. Some of those are the OIQ loss of self regulation in episode 65, breast implant recalls in episode 55, Kowloon Walled City in episode 45, and the Leaning Tower of Pisa in episode 35.
The US Interstate Highway System is a 78,465 km (48, 756 mile) series of multi-lane, divided highways that criss-cross the United States in a (somewhat) logistical order. Construction costs are estimated to be $558 billion in 2021 dollars with one-quarter of all vehicle miles driven in the country being on the Interstate Highway System.
The system connects all 48 contiguous states, with Alaska, Hawaii, and Puerto Rico having interstate highways as well.
US government efforts for a national highway system started in 1916 with the passage of the Federal Aid Road Act which provided $75 million over a five year period for matching funds to the states for the construction and improvement of highways. World War I prevented any significant implementation of this policy which expired in 1921.
EJ Mehren, a civil engineer proposed, “A Suggested National Highway Policy and Plan” in 1918 that consisted of 80,000 km (50,000 miles) of 5 east/west routes and 10 north/south routes. System passed through every state at a cost of $16,000 per km ($25,000 per mile).
In 1919, the US Army sent an expedition across the US to determine the difficulties that military vehicles would have on a cross-country trip. It took 62 days to drive 5,100 km (3,200 miles) from near the White House in Washington, DC to Presidio army base on San Francisco Bay. Convoy encountered many issues including poor-quality bridges, broken crankshafts, and clogged engines. Average distance driver per day was 82 km per day. I have hiked more than 82 km in a single day, so this isn’t exactly lightning speed. It was a long day but I’ve done it multiple times.
Then 28 year old, future President Dwight Eisenhower was on this trip, which we’ll get to later on.
1921 saw the Federal Aid Highway Act of 1921, which provided $75 million allocated annually and sought for the construction of interconnected “primary highways” with the intention of inter-state cooperation on transportation planning.
The Bureau of Public Roads asked the Army to provide a list of roads it considered necessary for national defense, which was compiled by General John J. Pershing in 1922, which consisted of 32,000 km (20,000 miles) of roads (The Pershing Map).
Automobile traffic increased throughout the 1920’s and 1930’s planners developed the largely non-freeway United States Numbered Highway System. The late 1930’s saw the planning of a new, large superhighway system.
The first formal description of the Interstate Highway System was put forward in 1939 by the Bureau of Public Roads’ Division of Information chief Herbert S. Fairbank.
Federal Aid Highway Act of 1956
Now President Dwight D. Eisenhower signed the Federal-Aid Highway Act of 1956 (Also known as the National Interstate and Defense Highways Act) into law which provides $25 billion for the construction of 66,000 km of highways, it is the largest public works project in American history at the time.
The Defense part is important for a couple reasons. Firstly, some of the original cost was diverted from defense funds. Secondly, one of the purposes was to provide access to US Air Force bases during a conventional or nuclear war with the Soviet Union or its communist allies.
Money for the Interstate Highway and Defense Act was placed in a Highway Trust Fund that was funded 90% by the federal government and 10% by states. Funds were generated through new taxes on fuel, automobiles, trucks, and tires. The federal portion is largely paid for by taxes on gasoline and diesel fuel.
Drew inspiration from Eisenhower’s experience crossing America in 1919 as well as the Reichsautobahn system that Eisenhower saw when he was the Supreme Commander of Allied Forces in Europe during WWII.
General Lucius D. Clay was appointed to head a committee charged with the implementation of the plan, Clay stated, “It was evident we needed better highways. We needed them for safety, to accommodate more automobiles. We needed them for defense purposes, if that should ever be necessary. And we needed them for the economy. Not just as a public works measure, but for future growth.”
Clay’s committee proposed a 10 year, $100 billion program which would build 64,000 km (40,000 miles) of divided highways linking all American cities with a population greater than 50,000 people. Initial proposal was to have a system of toll roads, proposal was scrapped due to not being feasible outside of populated coastal areas. Funded by previously mentioned gas tax.
Construction and Layout
Major East/West interstates end in 0 numbered and increase in number south to north
Major North/South interstates end in 5 and increase west to east
There are some major interstate highways that don’t cross into other states (looking at you Texas).
Medium interstate highways have either even or odd numbering, even is east/west, odd is north south. There are medium interstates that have the same number (I-76 is in Colorado as well as the interstate number of the Pennsylvania Turnpike)
Minor interstates have 3 digit numbers and the numbering is slightly more complicated. If the first digit is even, the interstate will eventually branch back into its parent (bypasses, ring roads, or beltways when they go around a landmark or a city). Odd numbered first digits are spur highways that don’t connect back to the parent highway. (I-294 is a loop that has connections to I-94 at both ends, I-787 would be a spur route attached to I-87)
The first state to complete mainline interstate highway construction was Nebraska in 1974 with the dedication of I-80.
I-5 that connects Mexico and Canada through California, Oregon, and Washington state was completed on October 12th 1979.
East-West completion of I-80 that runs from San Francisco to Teaneck, New Jersey was completed on August 22, 1986 and at the time of completion was the longest contiguous freeway in the world. Interestingly, the final section of I-80 to be completed was only 80 km (50 miles) from where the golden spike was driven that completed the first trans-continental railroad in the US.
The original Interstate Highway System was proclaimed to be completed on October 14th, 1992 with the opening of I-70 through Glenwood Canyon, Colorado. This section is considered an engineering marvel (neat!) with a 19 km (12 mile) span featuring 40 bridges and numerous tunnels and is one of the most expensive rural highways per mile built in the United States.
Interstates highways exist in Hawaii, Alaska, and Puerto Rico even though these locations don’t about other states or territories. Interstates in Hawaii start with an H prefix. There are 3 interstates highways and one auxiliary route that connect military and naval bases together as well as important communities on the island of Oahu. Alaska and Puerto Rico interstates are denoted A and PR respectively.
Mile markers on interstates generally start at the south or western state line if the interstate originates in that state.
Three digit interstates with an even first number that form a complete circle are numbered in a clockwise direction beginning just west of an Interstate that bisects the bypass near a south pole location.
Most Interstates round the distance based numbers to the nearest mile for exit numbers. I personally love this number for exits as it provides a decent approximation of how far it is to an exit as you drive by exits.
Fun fact, on I-19 in Arizona, the length is measured in kilometers instead of miles, as at the time of construction, there was a push for the US to convert to the metric system.
Highest point is 3401m (11,158 feet)’ on I-70 in the Eisenhower Tunnel at the Continental Divide in the Colorado Rocky Mountains
Lowest point is -16 m (-52 feet) at the New River near Seeley, California
Most interstates in a state: 32 routes in New York covering 2817 km (1750 miles)
Most primary interstates in a state: Illinois with 13.
As mentioned, the Interstate Highway System improves the mobility of troops to and from airports, air bases, naval bases, and army bases.
The Interstate Highway System has also been used to facilitate the evacuation of people facing hurricanes or other natural disasters with the removal of highway dividers so all lanes become outbound lanes. This procedure, known as contraflow lane reversal, has had mixed success.
Issues and Future Plans
More than 475,000 households and 1 million people were displaced during construction as highways cut through neighborhoods and residential areas.
Areas impacted were largely black and poor neighborhoods which led to increased segregation, physical buffers in communities, and served as a way to isolate communities of colour.
US Transportation Secretary Pete Buttigieg unveiled new efforts to address the problematic racial legacy of interstate highway construction with $1 billion to “reconnect cities and neighborhoods racially segregated or divided by road projects”
So there you have it, the US Interstate Highway System. A massive undertaking that started with a 62 day trip across America along largely unpaved roads that eventually led to the construction of more than 48, 000 miles of divided highway that crosses the United States and is a vital link in the lives of people, commerce, and military endeavors.
For photos, sources and an episode summary from this week’s episode head to Failurology.ca. If you’re enjoying what you’re hearing, please rate, review and subscribe to Failurology, so more people can find us. If you want to chat with us, our Twitter handle is @failurology, you can email us email@example.com, you can connect with us on Linked In or you can message us on our Patreon page. Check out the show notes for links to all of these. Thanks, everyone for listening. And tune in to the next episode for our first of a two part series on the history of Nascar race car safety.
Bye everyone, talk soon!