When most individuals hop in their and travel long or short distances on any given interstate, I would venture to say that many do not know much about the roads they’re on. Here are some fun facts about the interstate system.

 

History

In 1956, President Eisenhower signed into law the National Interstate and Defense Highways Act.  The original bill outlined the construction of 41,000 miles of highway over a 10-year period at a then mind-boggling cost of $25 billion.

The original intent of the Interstate, as in the name of the act, was for defense purposes; the roads and bridges were designed to handle military loading (equipment, tanks, etc.).  The original act called for the funding to be appropriated from a Highway Trust Fund that the Federal government would pay 90 percent and each state would pay the remaining 10 percent.

 

Interstate Numbering System

The Interstate numbering system designates that east/west routes are given even numbers and north/south routes are given odd numbers.  The routes are numbered from the west to east for the north/south routes with I-5 paralleling the Pacific coast and I-95 starting at Miami and terminating in Maine at the Canadian border.  Conversely, the east/west routes are numbered from south to north with I-10 stretching from Los Angeles to Jacksonville and I-90 starting in Seattle and meandering all the way to Boston.

 

What about Alaska and Hawaii?

Alaska has an interstate system made up of four highways that cover 1,082 miles. They are numbered A1, A2, A3, and A4. They are not built to Interstate Highway standards, but are small, rural, two-lane undivided highways.

Hawaii has four interstates, all located on the island of O’ahu. Unlike Alaska, they are all built to the same standards as mainland interstates. The interstates in Hawaii cover 1,013 miles.

 

Who Built the First Interstate?

While many existing sections of highway were incorporated into the Interstate Highway System, three states stake a claim to have the first section of interstate in the country.  Missouri awarded a contract (I-70) in early August of 1956 just after the June signing of the Bill to stake their claim for the first interstate under contract.  Kansas executed a contract (I-70 as well) on August 31, 1956 and began the concrete paving in September of that year to claim they were the first section of the Interstate System. The Pennsylvania Turnpike was opened in 1940 and was incorporated into the Interstate System, which leads them to boast to have the first Interstate.

 

Funding

The interstate system was initially funded from a user fee levied on each gallon of gasoline and diesel fuel sold and that still primarily holds true today.  However, through the years the Highway Trust Fund has diminished based on the fuel efficiency of today’s vehicles and the advent of hybrids and electrical vehicles that do not contribute to the funding since they buy little or no fuel. The Infrastructure and Investment Jobs Act (IIJA) that was passed last year shifted general funds to the Highway Trust Fund to keep it solvent but also added additional funding above the previous highway bill but did not change the funding source.  The IIJA bill included $1.2 trillion designated funding for water, broadband, ports, rail, airports as well as highways and other programs.  While this general fund transfer will bridge the gap, the Highway Trust Fund will continue to dwindle as less fuel per user is consumed.  While several states have implemented a user fee for electric vehicles, the funding source derived from fuel purchases will have to change at some point.  The use of Vehicle Miles Traveled (VMT) is the most common funding mechanism considered as the thought is that those who use the road will pay for the road and future maintenance.  Hopefully, the funding for our highways will be maintained and we will have the continued use of efficient and safe interstates and highways.

 

Safety!

Speaking of safety, as you drive though a highway construction zone, please drive at the posted speed limit and pay attention to the project as many SSR colleagues are on site working to provide these improvements.  Imagine if your cubicle or workspace was located within a few feet of a highway with trucks and cars zooming past at 70 miles per hour!