When you think of the most famous and busiest highways in America, the Interstate 90 (or I-90) will come to mind for many people. Named the #4 most traveled highways in the U.S. by the Federal Highway Administration, the I-90 has a recorded average annual daily traffic of over 320,000 vehicles.
In addition to being one of the busiest, the I-90 is also the longest interstate in the United States, making a journey of 3,085 miles all the way from Seattle to Boston. If you were to drive that route from the west coast to the east coast, it would take about four days, driving 10 hours a day to get there.
Driving this northernmost interstate, you would pass through 13 states, traversing all types of topography, over some of the longest bridges in the U.S., and see cities like Buffalo, NY; Cleveland, OH; Chicago, IL; Sioux Falls, ID; and Missoula, MT.
With that, you can imagine that not only can it make for a fun road trip, but the I-90 is used heavily in the transportation industry, connecting major arteries in some of the northern states. Read this post to learn how the interstate came to be and discover some of the most interesting stops along on this epic route.
Interstate 90 stretches over 3,000 miles from Seattle to Boston.
Interstate-90 was part of the 41,000-miles of interstate highways built as a result of the Federal-Aid Highway Act of 1956, signed by President Dwight Eisenhower that allocated $26 billion in federal funding to build these roads. The funding was created from a gas tax, which is still enacted today. President Eisenhower advocated for a high-speed national road system after seeing a similar system in Germany during World War II.
The interstate system was meant to serve as a military defense network as well as connect the country’s states and make the road systems safer than they were (many were still unpaved). This massive infrastructure project also helped rejuvenate the U.S. domestic economy after WWII, creating a plethora of jobs in building the highway, along with gas stations and other amenities along the way.
All of this helped create new opportunities for businesses and entrepreneurs. Today, there are 46,000 miles of interstate roadways.
To quicken construction on I-90, the route also uses some roads that had existed prior to the development of the U.S. interstate system such as the the Massachusetts Turnpike, which is also an example of the many toll roads the interstate follows as well.
The Turnpike is also a great example of some of the “bragging rights” of the interstate system, where seemingly unnecessary signs can be seen that boast the length of the route such as this one as you’re leaving Massachusetts, telling you for some reason that South Dakota is the next highest elevation. Just in case you need to prepare for the whopping 5-ft. increase.
Snoqualmie Pass in Washington state is known as a dangerous spot on the I-90. This area of I-90 connects you to one of the most beautiful mountain summits and waterfalls in the western states, however it has been one of the most difficult mountain passes to manage in the interstate system and conditions can be very hazardous.
The Snoqualmie Pass section of Interstate 90 is known for avalanche danger in the wintertime.
The Washington State Department of Transportation (WSDOT) warns drivers to numerous threats: avalanche, rock slides, rough pavement, traffic congestion, and wildlife. Winter freezing and spring thaws, plus wear and tear from snow plows and snow tires have worsened the road conditions over time in this area.
Over $400 million was allocated for improvements to Snoqualmie Pass East, including widening the corridor, fixing bridges, creating more chain-up areas, and rock blasting to prevent rock slides. The project includes building more avalanche bridges, which are raised above the road so that fallen snow and debris flows under the bridge, while traffic passes above.
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Here are some highlights of landmarks along the way either right off I-90 or a short distance away.
Quirky Places to Visit on the I-90:
Interesting sites to see along the I-90: Mount Rushmore.
Adding to the uniqueness of I-90 is the innovation happening on what’s one of the longest floating bridges. The state is adding a light rail route to the bridge, which has never been done on a floating bridge before. In fact, the project even won Popular Science’s 2017 Best of What’s New award given to Sound Transit, the agency managing and designing the project.
The goal is to alleviate the traffic on this main corridor connecting Seattle to its eastern counterpart across Lake Washington, Bellevue. Many commute to and from Bellevue as well as Redmond, both of which are on the other side of the lake. That means it’s pretty easy for routes to get clogged. Officials expect the project to be completed in 2023.
I-90 bridge to Seattle, Washington
Considering the history of the floating bridge, which once broke apart and several pieces sank into the lake in 1990, it’s understandable why adding more weight to the bridge is a concern. The bridge had to be completely rebuilt using different floating pontoon technology (apparently concrete blocks were maybe not the best option) and reopened in 1993.
The new rail system will be constructed to withstand and be flexible to six ranges of lake movements (i.e. different levels of waves and types of currents). The design alone has cost $53 million. It will certainly be a project to watch.
What's your vote for the next road to feature in our Busiest Highways in America series? Leave a comment below.
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