Relief Map

A History of Minnesota’s Interstates, Part One

Previously I’ve written a six part series of Minnesota’s trunk highway system. Now it’s time to go back periodically for topics that were skipped as outside the main story arc, or that were deserving of separate articles. One of these is the story of our interstate system.

The Dawn of the Dream

As late as 1919 Lt. colonel Eisenhower had indescribable difficulty on his cross country road trip trip. He was part of a military convoy from Washington, DC to San Francisco.  The endeavor took 62 days, and eventually trucks started getting stuck on a daily basis for hours at a time. (Today the total driving time is 41 hours). Here’s some photos from the Eisenhower Presidential Library.

Eisehower Road Trip


The convoy bogged down in muck and mire

Lt Col Eisenhower (left)

By the end of the trip there was no question in Eisenhower and the other participants minds that the federal government needed to be involved in transcontinental highways, and that’s what happened. The federal government did get involved in funding, setting standards, and a US branded highway system. Within two decades you could drive just about everywhere on pavement, and the biggest impairment to mobility wasn’t intractable mud, but traffic signals and traffic congestion. Road advocates started to dream big- of a national system of high quality highways. The idea was to provide a sink for government programs labor, ease civilian congestion, and facilitate military transportation.

Toll Roads and Free Roads

With the development of the Pennsylvania Turnpike in the 1930s the idea for a national system of tollways was tossed around. The Federal-Aid Highway Act of 1938, approved June 8, 1938 commissioned a national study by the US Bureau of Public Roads, predecessor agency of the Federal Highway Administration (FHWA).

The Chief of the Bureau of Public Roads is hereby directed to investigate and make a report of his findings and recommend to the Congress not later than February 1, 1939, with respect to the feasibility of funding, and cost of, superhighways not exceeding three in number, running in a general direction from the eastern to the western portion of the United States, and not exceeding three in number, running in a general direction from the northern to the southern portion of the United States, including the feasibility of a toll system on such roads

The report “Toll Roads and Free Roads” was presented April 27, 1939 to Congress. Here’s a map from the document.

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1939 Proposed Tollway System.


Here’s another map with proposed widths, I’ve highlighted the four-lane sections to make it legible.  Four lanes were considered justified at 1500 daily vehicles predicted by 1960.

Interstate 2 Vs 4 Lanes R

Roadway widths planned for selected system.

And proposed cross section. Lane widths are the 12 feet standard that’s still in effect today, but look at how close those trees are to the road.

Interstate Layout

Typical cross-sections proposed for toll-highway system

The study found the proposed system wouldn’t come even close paying for itself, being $1.7 billion short over the next 30 years (costs of $2,964,896,936, revenues $1,154,236,525) . Besides being ridiculously precise, we now know those numbers are ridiculous in general. Not even 1500 vehicles a day in western Ohio? They didn’t realize how much induced demand (or as I prefer to call it, latent economic activity) there was waiting to be realized with high quality roads. Although in my opinion it would have been unfortunate to have a system of tollways, it wouldn’t be so unfeasible as was presented. But having presented that, and on the theory that the report should be constructive as well as negative, a proposal for a more extensive system of free highways was made.


1939 free highway proposal

Reading the report it should also be clear freeways were envisioned in the cities from the very beginning. They were called “connecting routes”- not yet an integral part of the system. And there seems to have been a different amount of emphasis on them at different times and by different people, Eisenhower himself clearly envisioned something more along the lines of the Autobahns which did not go into the cities. The early technical distinction, the idea that the Autobahns were the prototype, and Eisenhower’s vision are likely where the myth that “we weren’t originally going to build freeways into the cities” came about. But this picture of a proposed “connecting route” should make it clear what was envisioned.

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Depressed urban freeway Proposal

In the end Eisenhower was overruled by the FHWA. It was felt that a system that didn’t serve the people with cars that lived in or needed to travel to the city was a poor model for America’s future.

The War Years and After

Soon after war came to the U.S, and our priorities shifted away from building up our infrastructure. The idea never died though, and planning for a national system continued. On April 14, 1941, Roosevelt appointed a National Interregional Highway Committee to study the need for a limited system of national inter-state highways. The report was substantially completed in 1941 but with the war going on there was no hurry to make the final revisions and wasn’t finally submitted to Congress until Jan 12 1944 (this report doesn’t seem to be available online).

The report recommended a 39,000 mile system. This wouldn’t have been all freeway or even all divided highway. Cross roads were allowed where the daily traffic was under 5000 vehicles, or basically just about anywhere in the country. A single carriageway was allowed with traffic under 3000. Amid the debate in Congress was the issue of the name, previously it had been known at the “Express” or “Interregional” system.  But Reps. Hugh Peterson (D-Georgia) and Leon H. Gavin (R-Pennsylvania) particularity disliked the term “Interregional”. It implied a country broken down into regions and de-emphasized the transcontinental nature of the highways.  The name “Interstate” came with the formal legislation to establish the system, the Federal-Aid Highway Act of 1944 that was passed on Dec 20, 1944. Here’s some illustrations from the report:

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1944 proposed Interregional Highway system . The dark blobs are population centers.


Relief Map

Relief map showing traffic volume of the proposed system.


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Proposed elevated highway


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Proposed highway to the city center.


The Federal Highway Act provided 50% federal funding for and established the system. Since we had other things to spend money on at the time, actual appropriations under the act were to come later. As it turns out they never did. President Truman worried the program would be inflationary and over-tax the construction industry, and his focus was more on housing programs. Another issue was that more rural states balked at only 50% federal funding. But planning continued on paper.

Interstate Highway Plan August 2, 1947 Big Text R


Note the I-29 between Fargo and Sioux Falls didn’t exist, it was a late addition to the system. Other than that the Midwest is identical to what was built. Here’s a 1951 map in the Twin Cities from the “Yellow Book”, which showed proposed intra-city routings.

Yellow Book R2

1951 Twin Cities interstate proposal

You’ll notice what became I-35W was intended to be along closer to Lyndale Ave. as opposed to halfway between Nicollet Ave. and Portland Ave. As  I noted in Part Two of The History of Minnesota’s Trunk Highways, Minneapolis business interests wanted the main trunk highway to the south to be along Lyndale Ave rather than Cedar or anywhere else, so there may have been some continuity of thought here.

The route of what became I-94 was the subject of much discussion. The diagonal to the northwest  was moved to be along the river. What is now Bottineau Blvd had been the main highway out of town since the auto trail days. But due to Minneapolis’s dream of building a vast industrial powerhouse with the St Anthony Falls locks and Upper Harbor Terminal the city wanted the freeway to directly serve those. In downtown Minneapolis a routing along Washington Ave was shown, putting it there was still under discussion into the 1950s. Between the cities the routing along University that’s shown is the one that got built, but there were alternative proposals. It would have been better to build it in the railroad corridor, but University Ave business interests and the desire for synergy with urban renewal dictated otherwise.

The Dream Becomes Reality

With the change of administration, the interstates had a champion. Eisenhower saw how much easier the interstates made military operations in Germany, here’s a famous photograph the U.S. army entering Germany over four lanes of smooth concrete instead of muck and mire, as well as the utility the had for civilians.


U.S. Army advances into Germany on wide concrete.

Although legislation failed in 1955, it succeeded in the following year and the 1956 Federal Highway act was passed in June 29, 1956. It formalized the name as the National System of Interstate and Defense Highways, and much more importantly it provided for 90% federal funding for a 41,000 mile system. This is also where the concept of  the entire system being full freeway standard was cemented. Though I-90 in Montana does not justify a freeway based on traffic volume, it does from a standpoint of having a consistent national system, and reducing long-haul motorist fatigue. Two lane interstates for volumes under 3000 were still allowed per the 1944 standard for a while, and in fact a number of two lane interstates got built in the western states and were not twinned until the 1980s.

The original concept was to maintain the existing numbering system with US designated highways, in 1957 came the idea for a separate numbering and branding for the system. Here’s a map of the numbers.

Interstate Highway Plan August 14, 1957 R

State employees were invited to submit designs for the shield. Quite popular were cutout “I”s, and also eagle motifs. Here’s a couple of photo-shopped submissions  And here’s a submission by a Minnesota Department of Highways employee. Minnesota at the time was just phasing out it’s star in a circle route markers, and at triangle in a circle is a civil defense symbol. The triangle was also supposed represent the highways spanning the U.S. and touching Mexico and Canada.

Minnesota Shield

The final design was a combination of a submission from Texas (which had the same basic shape and format but black and white and “I” instead of spelling out “Interstate”), with the red, white, and blue of the submissions from Missouri and North Carolina. I have no problems with the design selected. A shield motif has been associated with the federal government, and the design is distinctive yet legible and easily reproducible.

With all the pieces together it was time to get down to work and turn loose the bulldozers. Part Two will conclude with a decade by decade look at actual construction in Minnesota and a few thoughts about any potential future interstates.

About Monte Castleman

Monte is a long time "roadgeek" who lives in Bloomington. He's interested in all aspects of roads and design, but particularly traffic signals, major bridges, and lighting. He works as an insurance adjuster, and likes to collect maps and traffic signals, travel, recreational bicycling, and visiting amusement parks.