Put a Lid on It?

There’s quite a bit of chitter-chatter about lidding the I35W interstate through Cedar-Riverside, coming out of downtown. First, the Star-Tribune wrote about it. Then Charlie Zelle mentioned it at Policy & A Pint on January 16:

(Naturally, streets.mn got in on this conversation far earlier.)

Practical discussion of freeway lidding in Minneapolis is still in very early stages — no funding estimates, no operational plans, no legitimate proposals. But there are things we do know:

  • Lidding an expressway is expensive, with highly variable costs per mile/acre.
  • Many cities are using them primarily as parkland and public space. Now, don’t get me wrong, I love public space — but parks are a cost for cities, and only rarely a net revenue gain.

Let’s face it: Building is sexier than maintaining. Just look at the St. Croix River Bridge debacle, where Minnesota and Wisconsin are spending $675 million to build a controversial bridge to carry  total cost estimate is $580 million for a bridge that carries roughly 15,000 vehicles/day. Meanwhile, core Minnesota infrastructure is crumbling:

The idea of a lid is somewhat enticing. When we look at images of what highway construction did to Minneapolis and St. Paul, we can easily see how neighborhoods were split apart. The Institute for Quality Communities at the University of Oklahoma have an interactive look at Minneapolis as highways cut it apart. A lid provides a way to bring neighborhoods back together, with walking space. At the same time, lidding freeways also has a near-dystopian element, closing people away from the sunlight to create high-priced real estate.

Various sources point out that some of the construction costs of freeway lids can be cobbled together from local, state and federal funds, as well as the rights to develop on the “land” thusly created, with resulting tax base improvements. Obviously, this relies on actual development occurring, versus the creation of parkland. Even when construction is federally or state funded, landscaping of park spaces often falls to the city — Phoenix spent $5 million landscaping Hance Park. Some improvements on a lid in Cincinnati were financed by that city’s NFL team. Wikipedia offers a partial list of “structures built atop freeways” for inspiration.

Lidding I35W from downtown to U of M would likely cost more than the new St. Croix Bridge. Is funding this realistic in the current environment? What ideas do you have about freeway lids?

About Julie Kosbab

Julie Kosbab is an online marketing consultant and active transportation advocate living in Anoka County, Minnesota. She was one of Minnesota's only League of American Bicyclists Certified Instructors when certified in 2005, and is no longer lonely in that calling. A past member of the National Bicycle Tour Directors Association, she has 2 children and a garage full of bicycles. Find her on Twitter as @betweenstations, or read her (seldom updated) blog at Ride Boldly!

39 thoughts on “Put a Lid on It?

  1. Eric AnondsonEric Anondson

    Didn’t the design school plan for the 35W lid suggest a far lower price? Like $60MM? Whatever it was I recall it being unbelievable but it got everyone’s attention.

    1. Julie Kosbab Post author

      I haven’t seen that number, but it’s frankly unbelievable given the costs in other metros right now. The Dallas deck park was over $100 million once you factored in landscaping. I’ve seen numbers of $500 per square foot.

      Seattle was built in the 1970s and was $100 per square foot.

      I’ve seen some claims that it might be possible at $300 per square foot if you leave out things like interchange rebuilds and new ramps, but I suspect those excludes aren’t realistic for many projects.

    2. Jonathan Rozenbergs

      The $60 million cost comes from an initial estimate from a structural engineering consultant. Unlike other lids which need to use demanding structural gymnastics for achieving the required clearance, the lid proposal at 35W and Washington avenue has the opportunity to structured differently than the built examples in the rest of the country.

      The proposal that has been put out includes parking: the lid is essentially a parking ramp on top of the freeway, with a green roof on top. The A and B ramps where 394 comes into Minneapolis is essentially the same thing. The cost was estimated off of the same system: “what would it cost to build a parking ramp that is X-wide, and Y-long?” Ventilation strategies frequently increase cost, but in this instance, you can let the lid be vented naturally until there are buildings alongside it. At that point, each building that “plugs into” the ramp is responsible for a certain portion venting.

        1. Wayne

          Part of the Prudential center lid in Boston is a parking ramp. It seems to work since most of the street frontage is actual buildings that relate to the street. If it was just a ramp that would be terrible, but given the chance to wrap it in something else I might not hate it (and I hate cars and parking).

          This would especially work if you link it to the eastward skyway expansion and use it as an excuse to tear down all the parking ramps in the core and narrow the surface streets in downtown to make wider sidewalks. Keep all the cars in a ring of ramps like the ABC ramps (35W downtown exits next to the convention center is another great candidate for this) and stop using downtown streets as collectors/funnels to highway ramps.

        2. Joey SenkyrJoey Senkyr

          As long as there’s active uses fronting Washington, I’ve got no problem with parking ramps behind it. No matter what we do, there will be many people driving solo into downtown for decades yet. If we can get them to leave their cars effectively on the freeway instead of clogging the streets, that’s a win in my book.

        3. Eric AnondsonEric Anondson

          May be true that folks aren’t aware of that, but this may be a time to conceive a new scheme for downtown’s parking structures. I think it was in the 70s–80s the downtown planned to concentrate development in a tight core and ring it with parking, the tight concentration was thought to bring a better economic vitality that to let downtown development scatter all over.

          This arguably gave us the fantastic core, but also gave us the parking craters, especially in Downtown East that so bedeviled redevelopment around the Metrodome. Now downtown is spreading well outside of the old 80s parking ring.

          Maybe this could be a time where downtown starts developing a 30-year plan to pedestrianize downtown, to begin the removal of as much parking in the core as possible. If we are going to need parking for downtown drivers let’s move that ring of car storage out atop the highway loop. In order to keep the core with minimal car traffic, it’s entirely called for to build a few street car spurs out of downtown that run to the car storage lids than to. Part of paying to park in the parking structure lid gives you a street car ride into the core.

          It’s the kind of thinking I’d hope to see the downtown plan for the next 30 years try to achieve, if there must be parking, move it out atop the highways…

          1. Wayne

            As an addendum to what I said earlier … couldn’t they maybe issue bonds pretty easily to pay for the over-highway ramps since they’d provide an almost-guaranteed revenue stream to pay for them? Seems like that would defray a lot of the cost and then all you’d need is someone to wrap the ramp in development which should be easy. Plenty of residential demand downtown (and without the ugly highway in view it’d be more desirable) plus I’m sure some commercial space would do well with all the people who would be parking in the ramp.

  2. Jonathan Rozenbergs

    The lid in Dallas, Klyde Warren Park (roughly the same size as the proposal for 35W in Minneapolis), was built for $106.7 million. The park will create $312 million in economic benefits, and $91.1 million of tax revenues from increased property values.


    When strategically located, lid projects pay for themselves.

    Where the proposal for 35W is stronger is in the way a freeway lid in that segment makes the underutilized land next to the freeway attractive for development. Currently there are 18 acres of open land next to the freeway at Washington Ave, right between downtown, the University, and the densest neighborhood in Minneapolis. That kind of underutilized land in such a location is typically an economic sink for any city.

    Lidding the freeway at 35W and Washington makes those 18 acres useful for buildings. When the proposal was presented at the IDS Center last May, the economic argument was at the forefront. Currently, there are only four tax-producing parcels in the 18-acre area which annually yield about $8 million in property taxes. Putting a lid on that segment of freeway would make an amenity that would allow nearly 5 million sf of development to be built next to it. This translates into a neighborhood of about 5,000 people and 14 parcels generating $288 million over a 10-year period.

    A lid like that, even one like Klyde Warren in Dallas, provides a revenue stream for the primary property owner of freeway rights-of-way — MnDOT — to use for highway maintenance elsewhere.

    So that’s the economic argument. Let’s talk about why we should lid freeways. Not only have freeways disconnected our neighborhoods, they cause incredibly harmful air pollution 400-feet (up to 1,600 ft) away from the road, and they decrease property values as well. When one looks at the demographics along freeways, we find that it is typically the underserved, underrepresented, and impoverished segments of our population that are stuck living next to them. Not only are we segregated are most vulnerable population, we’re poisoning them as well.

    For further reading on highway lids in the Metro Region, please visit:


  3. Wayne

    “At the same time, lidding freeways also has a near-dystopian element, closing people away from the sunlight to create high-priced real estate.”

    You mean drivers? Yeah, I think we’ve been bending over long enough for their benefit. They can drive in a tunnel for a few blocks.

    1. Sean Hayford OlearySean Hayford Oleary

      Agreed here. In fact, especially this time of year, motorists might *prefer* driving through a (clean, dry) tunnel versus having sky views. Regardless, I wouldn’t make any policy decisions based on it.

      Although I do think this has value, I’m not sure how to weigh it against other regional transportation needs. The discussion of a lid at Grandview in Edina — where the interchange is much simpler and the air rights might actually pay for the lid — seems like a better first foray into this.

      If cost were no object, of course, I think it would be great to have the entire 94/35W beltline around downtown lidded/buried.

      1. Jonathan Rozenbergs

        Seattle has four freeway lids that have been completed with three additional either in construction or design development. Collectively, they help entertain the idea of a corridor-wide strategy.

    2. Julie Kosbab Post author

      For what it’s worth, I’m thinking of countless science fiction works and movies in which the poor are stuffed underground to serve the needs of the rich on the surface. I was a lit major in college.

      1. Wayne

        Fair point, although in this case I’d say the roles are reversed. Generally those commuting by car from a far off suburb are probably better off than the city residents who live adjacent to the freeway and deal with the smog/noise/lack of connectivity.

    1. Wayne

      This reminds me of the way old cities used to have houses/shops on the bridges across rivers. It seemed to fall out of fashion a while ago, but bringing it back for highways is a great idea.

    2. Daniel Herriges

      I like the Columbus idea a lot… with limited resources, I’m all for “good enough” solutions that address the worst problems created by that freeway trench at potentially far lower cost than burying it completely.

      I also like the series of tunnels that take I-35 through its last couple miles in Duluth. Ideal? No. Better than nothing? Absolutely. And it seems to me that something like that doesn’t have to preclude capping more of it at a later date.

  4. Adam MillerAdam Miller

    I hate to be too negative, but we may need some sort of Godwin’s Law rule about the Stillwater bridge, the mention of it immediately makes me want to stop reading, and I’m sure others have the same reaction. Maybe that’s not fair, but I’d say use it as an example with caution.

    As to lids, as a dream I absolutely love them, given how horrible a massive, noisy, smelly freeway in a ditch is as a neighbor.

    But as Julie points out, that’s completely beside the point if lidding isn’t economical. Can you get enough usable space to pay for them? Gee, sure seems like you should be able to in the right spots, but I’m no expert.

    Totally agree that it should not be done to create only park space.

    1. Monte Castleman

      You’ll probably want to skip my next series of articles on the Stillwater Bridge then where the probability of it getting mentioned is exactly 1. (Although I’m trying to do it more of a history piece than a propaganda piece, whatever you feel about the meritst I would hope most people agree it’s interesting from both a historical and construction porn type of views.)

      The rule I follow on the forum and a roads forum I frequent is that I’ll post pictures and discuss technical aspects and construction, but arguing with people about the merits is pointless and tiring at this point. Obviously my enthusiasm for the project can’t entirely be separated, but I try to avoid unproductive comments like “this is one of the greatest things ever” and in turn ignore the “this is a big waste of money” comments rather than trying to argue.

        1. Monte Castleman

          I was joking about avoiding my article of course, (but that is what I’m working on, a three part comprehensive history of some of the studies and planning behind the bridge, alternating with the three parts left of my traffic signal series)

    2. Julie Kosbab Post author

      Also, note that some of the conversation is about capping near Cedar-Riverside. If the land created drives property values upward, are we about to (god I am saying this and I am so sorry) gentrify a significant population out of the area, rather than improve the area for the residents already there?

      Livability and developing wisely are essential. But we also have to balance the idea of “we will pay for it through tax revenues as the additional “land” and the nearby properties appreciate!” with the needs of existing residents.

      1. Adam MillerAdam Miller

        “If the land created drives property values upward, are we about to (god I am saying this and I am so sorry) gentrify a significant population out of the area, rather than improve the area for the residents already there?”

        I’m not sure these are two different things and I don’t think you’re doing anyone any favors by keeping an area “bad” (obviously, as gross oversimplification) in order to avoid “gentrification.”

        That said, I’m not sure Riverside Plaza is every going to be in much danger of gentrification.

        1. Julie Kosbab Post author

          Right. I’m not saying keeping an area “bad” does favors, but we’ve not done well with “improving an area” and maintaining affordability for the present residents.

          There’s actually considerable flight of the working poor to the suburbs right now that’s got some real challenges — from transit access, to services access.

        2. Wayne

          I don’t particularly think the east african immigrant population will be driven out anytime soon. In a lot of cities you have ethnic enclaves that establish themselves and generally are pretty resistant to being ousted by gentrification. How many cities’ “Chinatowns” have disappeared as the areas around them gentrified? I’m sure it’s probably happened, but it seems like that would be the exception and not the norm.

  5. michael

    They’re Going To Bury A Stretch Of German Autobahn And Cover It In Parks

    Hamburg’s plan to hide its highway underground and cover it with green space will reconnect a divided city.

    When the A7 highway was first built in Hamburg, Germany, it sliced the city in half. Now a few divided neighborhoods are starting to be stitched back together, as the city begins construction on three new parks that will fully cover parts of the autobahn.

    The highway is the longest in Germany and one of the busiest. As traffic keeps getting worse, the city realized that it had to find a way to keep the noise in the area low enough to meet national laws for noise pollution. Since simple walls wouldn’t be enough, they decided to turn sections of the road into covered tunnels. The design can reduce noise in surrounding neighborhoods to almost nothing.

    1. Wayne

      Wow, that plan looks remarkably similar to something I threw together a while back (before I was pestering you fine folks here). Great minds think alike, I guess. ( ;

  6. David LevinsonDavid Levinson

    We’ve been talking about Lids for awhile. See Not Dead but Buried https://streets.mn/2013/01/14/not-dead-but-buried/

    That said, don’t dismiss parks as a money loser. The land value around parks is higher than comparable land elsewhere (would Manhattan be as valuable without Central Park?), so whether the park gains enough tax base to offset construction costs is contingent on the case.

    I like the idea of a small set of buildings adjacent to the bridge, as in Columbus’s Cap, so from the street grid you don’t see the Freeway. Again whether this is net gainer or loser depends, but creating leasable space, and connecting two neighborhoods (Downtown East and Cedar-Riverside/West Bank) with a contiguous street of retail activity (Washington/Cedar) should have some spillover value above and beyond the rents on the lid itself.

  7. Luke Van SantenLuke Van Santen

    How do lids improve air quality? Do they allow collection and then discharge at a specific point instead of all along the corridor?

  8. Evan RobertsEvan

    It’s interesting to see the opposed perspectives here
    “It will drive up property values and thus drive out poor people in affordable housing”
    “By adding more land in an area with abundant undeveloped land (surface parking lots) the only thing to do will be to make a park out of it.

    How this plays out depends on the size of the lid (and the land released) and the amenity value of the new land for the adjacent buildings.

    Here’s the thing though, most lids with substantial amenity value to the surrounding neighborhoods will also be large lids since the disamenity of the freeway is precisely its huge ugly footprint. So it’s just hard for me to see how a lid would raise land values in Cedar Riverside that much.

    The only way that would be possible would be if the lid were large and developed as a fabulous new park giving the Cedar Riverside towers a prime view. Hard to see that happening.

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