Not dead, but buried

About 150 years ago, London, then a metropolis of 2.8 million people, opened the Metropolitan Line, the world’s first subterranean railway. (There are many good histories.)

Why did London go underground? It didn’t want its core (The City of London) sliced up with railways going hither and yon. It was not an unconsidered decision, the whole process of first ensuring lines did not cut through the City established early on (the first Railway to London was 1838), the Report on Termini recommending the Underground in 1856, with opening in 1863. While many US cities, including St. Paul, managed to build Union Stations, London was practically circumnavigated by about 17 major surface railway stations terminating lines to the rest of England. The Metropolitan Line was built to connect the northern slew of them, from Paddington through Marylebone, Euston, St. Pancras, King’s Cross to Farringdon. It was built underground of course, so as preserve surface level connectivity, in the case of London, mostly existing local streets. They used cut-and-cover construction. It was a phenomenal success (and profitable!), and was quickly replicated throughout London. Other cities eventually caught on. Today Asian cities are outbuilding them all.

About 50 years ago, Minneapolis St. Paul, then a city of 1.6 million people, opened I-94 and I-35, freeways connecting the city to its suburbs and to other cities in the US. (There are also many good histories.)

Unfortunately, Greater MSP learned nothing from history and did not go underground in the core cities, and we see the result today, downtowns disconnected from the rest of the region by highways. People close enough to walk to the core who cannot.

The idea of underground highways is not new. In 1940, Robert Heinlein penned The Roads Must Roll. We have had tunnels underground as well as under water. Even the Twin Cities has a land tunnel under the Lowry Hill to preserve the neighborhood above.

Unfortunately the Big Dig has given such roads a bad name. Fortunately the Twin Cities does not require any more digging, we just require bridging, many miles of Twin Cities roadways are built in trenches begging to be capped. There are many examples nationally to draw from.


The experience of Air Rights in Minnesota is not vast, but it does exist. In Duluth there is a park built above a Freeway. An advantage of parks is that they do not require Benefit/Cost Analysis, unlike some other investments. In Minneapolis, we have both parking ramps and the Twins Stadium built atop I-394. Part of the University of Minnesota crosses what used to be the Washington Avenue Freeway Trench.

But we can of course do so much more. When I was teaching Networks and Places a few years ago, we often selected as group projects the design of an Air Rights/Land Bridge project across a Twin Cities freeway section. The whole exercise was written up here from a pedagogical perspective. The specific ideas generated (linked below) varied from plausible to implausible. The general concept remains valid, freeways in Greater MSP dismember the urban fabric, and we need to sew patches to restore the structural integrity of the transportation mesh.

Think about I-94 between St. Paul and Minneapolis. Most of it is entrenched. Much of it could be bridged creating viable land uses. This is not cheap, and surface parking indicates land is not yet sufficiently scarce we need to create more of it, but it is about more than just creating developable properties or parking ramps, it is also about accessibility, walkability, and a city worth living in.

We could think about the best sites to do this on. I would start with roads crossing the freeways without exits to the freeways. The reason is the simplification of traffic movements, and reduced costs, as well as more success as sidewalk facing land use.

We could also think about which land uses to enable. Parks are always popular. Retail in retail districts is as well. Parking ramps over freeway Bus Rapid Transit (the Orange and Red lines) may be appropriate. If buildings they may simply front on streets, or they might cover entire blocks, especially if parks. There are costs the larger they are, with ventilation and other mechanical systems to be considered, as well as structural systems and construction complications.

The most obvious are the following (from West to East):

I-94 in Minneapolis

I-94 in St. Paul

Mn 280

  • Larpenteur Ave
  • Territorial Road
  • University Ave
  • Franklin Ave

I-35W in Minneapolis (from North to South)

I-35E in St. Paul (from North to South)

  • W. 10th St
  • W. 5th St
  • Grand Ave
  • St. Clair Ave
  • Randolph Ave
  • Fort Road / 7th Street W

italics indicates freeway conflict

Of the identified sites, I would vote for Nicollet 1st and Chicago 2nd, Hamline 3rd, Cedar 4th, Franklin (I-35W) 5th based on market potential and ability to better connect communities.

Did I miss any? What others should there be?

Your job: make the case for the best potential Minnesota freeway cap, what it should be, and why in the comments.

20 thoughts on “Not dead, but buried

  1. Eric

    As I live right at 38th St and 35, I live and breathe (literally) the freeway every day. The connections across the freeway there are terrible and quite dangerous, especially Stevens Ave and the 38th St. bridge intersection. Pedestrians and bicyclists do make the trek across the freeway but I see people have to hop into the road all the time because the sidewalk is about 4 ft in width and it gets easily crowded (when I walk my dog to MLK Park I usually have to go in the road if someone is coming in the opposite direction, just not enough room for all of us). I'd love to see Lake St to 46th capped, especially love to see MLK Park expanded!

    Thanks for shining light on this topic. We do have a plethora of great options.

  2. David Greene


    All of your I-94 suggestions are limited to areas south or east of downtown. As usual, nothing for North Minneapolis.

    Please, examine suggestions not just from an engineering standpoint but from social aspects as well. Failure to consider equity issues is why tragedies like Rondo happened in the first place.

    1. Justin FoellJustin Foell

      David, I agree with you… I-94 west between downtown and I-694 is one of the widest swaths of freeway in the metopolitan area. It's placement is unfortunate as it completely isolates a nice section of riverfront from its (potential) users.

    2. Nick MagrinoNick

      Fantasy aside, it might be because you can buy entire blocks in North Minneapolis for a couple hundred thousand dollars? This is an incredibly expensive idea even in Downtown Minneapolis, where property values are very high and there's lots of already vacant land. It's not a bad idea, but we still have at least a decade of infilling to go before this would really be plausible. Furthermore, much of I-94 through the northside (the disadvantaged parts that I assume you're offended aren't listed here) borders industrial uses on one or more sides.

      1. David Greene

        They won't be industrial once the upper river redevelopment gets underway.

        The point is that we need to intentially THINK about and act upon equity principles. It's very easy to get stuck in our status quo thinking and acting. We have to unlearn what we've learned and look at things from new persepctives.

        1. Bill LindekeBill Lindeke

          how about we build a LRT through North Minneapolis, along Penn Avenue maybe? that would be a great investment for a part of the city that often gets left out.

          1. Matt SteeleMatt

            Wasn't there a plan to bridge over 94 near Lowry as part of a master plan for a riverfront park? Or was that a plan from that group with all the Mississippi reuse ideas and charettes?

          2. David Greene

            Bill, please talk to residents of North Minneapolis. The community is plit pretty much 50/50 on the Broadway/Penn alignment.

            I think an alignment all the way down Broadway would be win-win for everyone but that got nixed a while ago.

            I'm not willing to demolish hundreds of houses unless a good majority of the community wants it.

  3. Bill LindekeBill Lindeke

    I'd say that 94 South of Downtown (particularly around Nicollet) and 94 directly adjacent to St Paul's downtown are two great candidates that don't seem overly wide.

    Also, we need to bridge the huge gap at 35W and Washington, somehow, to re-connect the University and Cedar-Riverside to downtown. This, though, is impossibly wide (much like 94 at along North Minneapolis.)

    1. Xan

      There is plenty of room for LRT in the 94 trench, it could be part of the build-over process. In exchange for development rights above, developers would have to put LRT capable track in their basement, since there should be no costs for land acquisition. The resulting line could support development along the riverfront and begin the connection with the neighbourhood on the other side of the freeway. (See Value Capture : The land east of 94 is far too valuable for its current use, which is what it was suitable for 100 years ago. But it would make a fantastic dense neighbourhood. (The buildings would face the sun and downtown – you can't do that in South.)

      There are better (and cheaper) solutions for the rest of North than LRT down a street that is too narrow to support it.

  4. Evan RobertsEvan

    I-94 from the Lowry Tunnel to Riverside Park, and I-35 from 22nd St to the Mississippi. That's a fantasy and a goal.

    I think if this was to occur it would obviously come in stages, and have to leverage private investment, or be supported by it. As a first stage I think anything over I-35 between 6th St to 1st St would be a good place to start. Why? It's an area where there's a lot of private development already occurring as it's close to 2 current and 1 future light rail stops. A land bridge would re-connect two growing areas.

    The area is already mixed-use, so it would be likely to generate a lot of pedestrian traffic.

    I think they key to making these things work is to envision buildings as a central part of the design, rather than parks. Yes, include reasonable green space on the land bridge, but the idea that people will use a park on top of a freeway (in a city with lots of much better parks) is a waste of a good idea.

  5. Matt SteeleMatt

    I have a work in progress for rebuilding the grid between DTE and Cedar-Riverside:

    This infrastructure is getting old, despite incremental changes such as the new ramp from 4th to NB 35W. Yet at some point it would be just as cost effective to bridge the grid back into existence, open up multiple blocks for redevelopment instead of loops and wide ROW for a freeway-esque trench. Then some sort of incentive for air-rights development over a few blocks, starting with facing Washington Ave over 35W. What a change this would be for the neighborhood.

  6. Dan Fehler

    First, I'd cover I35W between 40th and 42nd street, expanding ball fields at MLK Park.

    After that, I'm not sure. Too many options, but not many logical "needs" that fit the topography.

  7. David LevinsonDavid Levinson Post author

    A former student sends along this:

    First, I got a hold of an interesting document many years ago from the City of Minneapolis on Capping Freeways. Can't find it any more though, they may have a copy sitting around.

    Secondly, ODOT and the City of Portland just got done with a planning effort including land use and transportation plans, and several years of negotiating. You can find out more detail if you'd like at the website below. We are proposing two lids (for a variety of reasons). One thing often overlooked as a benefit is lids offer great construction staging options.

    Just thought I'd 1) brag (first time ODOT and City agreed) and 2) offer information if you'd like. SR 520 project in Seattle is also proposing many lids.

    There are some nice watercolor drawings of freeway caps in the document. Watercolors can make any infrastructure look good though.

  8. Xan

    Whoops, that was supposed to go above, but my Internet connection is crap, so it put it here when I tried to add a comment to this comment.

    Now back to 35W and Washington:

    It is not really that wide. Sure the area looks wide, but the freeway is not that wide, and that is what you are covering. By adding a bridge that connects 3rd to the West Bank, you eliminate the need for all those ramps connecting the Wash trench to the freeway. That leaves a lot of space to build and a narrower area to cover. That is land squeezed between downtown and the University, right next to a new stadium, and it is half dug out, i.e. it is valuable.

  9. Froggie

    I don't think your 2nd St overpass will work, because of clearance issues with the SB off-ramp off 35W.

    Mind if I borrow this to play around with in GIS? An intriguing concept. Like the bike connections. 4th St not so much.

Comments are closed.