What’s Better Than A Lid? Remove I-5 Entirely From Central Seattle

Seattle without I-5 between I-90 and SR-520. (Google Maps, with edits by author)

Seattle’s Interstate 5 is in rough shape. Maintenance has been deferred so long that a full rebuild is likely necessary, as former Washington State Department of Transportation (WSDOT) secretary Douglas MacDonald detailed in this article. Momentum is building to lid I-5 in Downtown Seattle to mitigate the impact of the freeway and add park space; it even got a mention in the adopted Seattle 2035 Comp Plan.

Before moving forward, we should probably ask the hard question: should I-5 bisect our center city in the first place whether lidded or not? We don’t need I-5 in Seattle’s core because it provides so little in the way of mobility while costing so much in wasted land and in pollution and the adverse health effects associated with pollution.

For several hours a days, the freeway and extensive network of interchanges are gridlocked into a major obstacle rather than an asset. And to make the loss all the worse, the land adjacent to Downtown, South Lake Union, and Eastlake is extremely valuable. If you haven’t noticed, land in those neighborhoods is worth a crazy amount of money. The Seattle Times got $62.5 million for two full blocks it sold to Onni Group in 2013. Removing I-5 between I-90 and SR-520 would free up more than 50 blocks by my rough calculation, which could mean more than a billion dollars worth of land.  Stricken with budget shortages, Washington State Department of Transportation (WSDOT) might be forced to sell off Downtown Seattle land to finance its tireless efforts in suburbia.

Why has maintenance been deferred so long? It could be WSDOT is stalling until Sound Transit builds out ST2 to Lynnwood and Federal Way. Or the department could be stalling until it figures out where the heck it will secure the billions and billions necessary to maintain such an overgrown and tired freeway. The state legislature passed a $16 billion transportation package in 2015 but focused on highway expansion rather than catching up on I-5 maintenance. Road maintenance isn’t sexy.

Building I-5 decimated Seattle neighborhoods it crossed. (WSDOT)
Building I-5 decimated the Seattle neighborhoods it crossed. (WSDOT)

So what would Seattle look like without a freeway blasting through its core? Here’s what it looks like now followed by a little mock-up I made with much of the street grid restored and the freeway gone.

Seattle today with I-5 ripping through its urban fabric. (Google Maps)
Seattle today with I-5 ripping through its urban fabric. (Google Maps)
Seattle without I-5 between I-90 and SR-520. (Google Maps)
Seattle with I-5 removed between I-90 and SR-520. (Google Maps, edited by author)

Eastlake and South Lake Union flow smoothy into Capitol Hill without I-5 in the way. First Hill suddenly becomes integrated with Downtown and Pioneer Square, providing much easier and more pleasant pedestrian access. The hole blasted in the International District disappears. Intersections that used to cause big problems for bus reliability like Denny Way and I-5 would move more steadily rather than getting backed up from on-ramp traffic. And in I-5’s absence, Sound Transit’s growing light rail network can pick up the slack to carry commuters Downtown.

But what about interstate traffic and interstate commerce? Well, I-405 can handle north-south interstate traffic. I-405 is in pretty solid shape, unlike I-5, and growing in size. Meanwhile, I-90 would still carry freight from the Port of Seattle into the interior of the state and vice versa. In fact, extracting the clogged artery of I-5 Downtown may actually improve traffic flow to the Port of Seattle by lessening the induced demand and simplifying nearby interchanges.

The federal department of transportation may protest at the removal of a core interstate freeway it built. That said, the federal department of transportation is quickly finding itself financially insolvent as its gas tax revenues dwindle, in large part due to cars becoming more efficient and less reliant on gasoline. Meanwhile, Congress has shown little interest in implementing other road user fees high enough to fully compensate; it used gimmicks to fund the last federal transportation package. In other words, the federal department of transportation may not be in a position to protest or require the maintenance of its many overbuilt arteries.

The beauty of this plan is that I-90 and SR-520 still serve cross-Lake Washington traffic and feed the freeways headed out of Seattle. It’s actually fairly conservative. We keep some freeways in Seattle, mostly north of the Ship Canal and south of the stadiums, but eliminate them where they do most harm and squander valuable land most egregiously. We’d also have the extravagant Bertha-drilled tunnel to feed SR-99 traffic relatively unobtrusively, if expensively, through our downtown core. (That is assuming the tunnel is completed–the tunnel is about half done, even if the source of the funding to finish off the project is in legal limbo.)

This rendering hints at what Patano has in mind for the freeway cap in East Lake where I-5 is elevated. It appears the protected bike lane would be at street level and the park seven stories above. (Patano Studio Architecture)
This rendering for a freeway lid in Eastlake shows the limitations of the lidding approach: even after expensive mitigation, it’s still not a high quality urban space and there’s minimal east-west connectivity. (Patano Studio Architecture)

Plans to lid I-5 Downtown are intriguing but they add a billion-dollar-plus project onto a multi-billion dollar maintenance overhaul. It’s not inconceivable money could be secured, but it’s also not fiscally prudent next to the more salubrious and human-friendly option of not rebuilding the freeway where it never should have been in the first place. Lids also need to be reinforced at significant expense to support dense housing overhead. Simply eliminating I-5 and restoring the street grid means we can build as high as we want on the salvaged land.

The Downtown section is already adjacent to 40-story towers or soon to be. Imagine 40-plus-story towers taking the place of bumper-to-bumper automobilia doing little good to anyone but belching pollution into some of our most densely populated neighborhoods. While we are being ambitious, imagine high speed rail linking us to Portland and Vancouver running in a cut and cover tunnel where I-5 once ran. I-5 provides real estate that is straight enough to run high speed rail, which, in an era of priced carbon, will be very competitive with airline travel. That represents the future much more so than freeways in urban cores.

The City Council just saw fit to preserve a section of the “Ramps to Nowhere” for the next completed R.H. Thomson Freeway. Supporters said they wanted to commemorate the citizen activists who prevented an expressway from blasting through the Central District and Montlake. That was a worthy fight, and I can buy the argument it’s worth a memorial.

That said, let’s not only nourish ourselves with nostalgia. Let’s continue our worthy fight against urban freeways. We can undo the wanton freeway-building damage of the past. I-5 doesn’t need to blast through our city center. We Seattleites wiped the R.H. Thomson Expressway off the map; we can do the same for I-5.

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Doug Trumm is The Urbanist's Executive Director. An Urbanist writer since 2015, he dreams of pedestrianizing streets, blanketing the city in bus lanes, and unleashing a mass timber building spree to end the affordable housing shortage and avert our coming climate catastrophe. He graduated from the Evans School of Public Policy and Governance at the University of Washington. He lives in East Fremont and loves to explore the city on his bike.

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Completely ridiculous and I can’t believe anyone would think this is a good idea.

Steve Corley

I only just saw this post. I like the idea but suggest the alternative that a 4 lane roadway (2 nb, 2 sb) run from I-90 to 145th with no access within Seattle north of I90. This limited access road provides through access (trucks, anyone not stopping in seattle) and a boulevard with reconnected grid lays on top. Over the ship canal the “I-5” road takes the lower deck, and the upper deck is local access traffic and light rail tracks. I know many users are just jumping on the freeway for a couple exits (I do it all the time) and often this is simply because the severed east/west connections (where my mother’s house used to be) make the freeway the easiest route to get across. Hopefully the depth of the LR tunnel between convention center and Capitol Hill wouldn’t be a barrier. The regained property along the right of way could be sold off to help pay for the project and after development would provide a nice boost to the tax rolls. I think that keeping the N/S through route would make this more politically possible. Nice idea, I had started musing about it myself lately and I am glad I am not the only dreamer.

Steve Corley

A fine idea.

Leon T

Wait, has the population of the greater Seattle area gone up, or down in the last 20 years?

And you want to take away the main north/south route? And you think that will make mobility better?

You’re a funny guy … now tell me the one about how bike lanes and traffic “calming” help get people form point a to point b.

Alex Mandel

It’s a good idea, requiring 405 to be expanded at south and north points (this should become I-5 by designation). It would also require incoming traffic to have a few more routes for N/S travel, and extending I-90 to 99. The thing is a blight, and it makes East West travel a pain, and generates so much traffic that gets in the way of people who drive/bus/bike but don’t want to use the freeway.

What I have not seen considered is how the freeway encourages people to plug it up with local traffic. People get on at Mercer and exit at Montlake. The left to right entrance exits already slow down traffic a lot, and really, there are only two full-time lanes going through the city from North and South, I think we would be surprised how little actual through traffic there is.

It’s politically difficult, if not impossible, barring an earthquake that shuts down the freeway for years until people realize they can get along without it. It would be feasible as a 15 year long term plan, depending on better transit and development patterns going in place before the final closure.


Let’s remove I-405 too. You want to “improve cities”? Don’t just focus on Seattle. You want to get revenue from selling land under a freeway? Check the real estate prices in Bellevue downtown.

Let’s remove I-5 *and* I-405. We can route all the traffic between Tacoma and Everett over Blewett Pass. Or does the Wallingford-Fremont bloc not care about the east side?

Rocky Waters

Excellent idea. Interstates should not run through any major city. Detroit was destroyed in part by chopping it up with multiple expressways. Put the maintenance money into 405.


Keep smoking that weed…


“But what about interstate traffic and interstate commerce? Well, I-405 can handle north-south interstate traffic.”

You have got to be kidding. I’ve seen some pretty stupid ideas over the years, but this one has to be in the top 5. And I’m a liberal.

Phillip Burger

Take out I-5 on the map as shown. Go further and re-designate the existing I-405 as I-5. Call I-5 north of 520 and south of I-405 something like I-905. Likewise with the existing segment of I-5 between I-90 to I-405. This is the opportunity to rebuild I-405 into the high-volume spine it should be.

Finally, it’s recognition what a mess I-5 was. They didn’t even include rail right of way in the median because it was too expensive at the time! And, it’s a very long bridge south of I-90 to Georgetown.

When relatives come to town, they find it interesting that if any one of the pillars were compromised due to any number of causes, it would likely result in all lanes in that direction being shut for days or longer. Disbelief ensues.

Maybe $8 billion to rebuild? It’ll never happen. Forget the lid. Take out I-5. The time has come.


Why keep the I-5 spur from 405 to 520? Rename 405 as I-5. The section of I-5 from I-90 south becomes a new spur (I-505?) Through traffic now continues on the “new” I-5. Freight traffic has easier access to points south and east. Removing I-5 north has the bonus of freeing up space next to light rail stations for urban villages. (The land sales can help fund additional transit, pedestrian and bike improvements.)
To help reduce demand on local roads, we can add tolls on the ship canal bridges.
Would removing the freeway be a radical change in transportation? Yes, just as demolishing a section of the city to build the freeway was a radical change. People are very adaptable. If we just tore down the freeway, there would be plenty of complaining and forecasts of traffic Armageddon, but after the dust settles, people would probably not imagine going back to the old ways.


One of the stupidest articles I have ever read.


Bury the freeway and use the “lid” to build a bicycle highway and linear park. Unlike an Alaskan Way viaduct park, that would indeed rival NYC’s Highline park. Not everything has to be replaced with luxury apartments or other high rise buildings.

Patrick Spence

The only way this could work would be if the sr99 tunnel was doubled or tripled and extended to eastlake, with the 99 being redesignatedd as the 5, which would actually make a lot of sense, if someone would pay for it all. Alternatively, we could expand the 5, but pedestrianize a ton of roads downtown.

Ian Scott

Maybe be after ST3 passes and is built out and the I-405 expansion finished so 16-25 years from now. I already go around the lake when i go from south Bellevue to Shoreline I go north on I-405 and down I-5 because the traffic is quicker even though it is a longer distance. Probably should wait for the “rest of the west” to get finished too. Dumping 520 and mercer st as the start of I-5 would be the best way to fix the mercer mess. If I-405 become the main arterial It will get designated I-5 and the two spurs that head in to Seattle from the north and the south will get renamed as well.


This is an utterly ridiculous proposal. Freeways are a very necessary part of a city’s transportation system. I-405 can’t handle the amount of traffic in its current state and would probably have to have at least two lanes added along its entire length for it to have at least adequate capacity (maybe) for additional traffic it would be carrying.

I wouldn’t mind completely burying I-5 in a tunnel through downtown, but it is totally irresponsible to just get rid of it completely.

Campbell Sadeghy

Removing I-5? Ha! Not ever going to happen and thankfully we have sensible people in charge and not rash thinking new urbanists. Next up, let’s remove the 101 and 110 through downtown LA for walkability! Here I am sad the Beverly Hills freeway didn’t get built.

Patrick Spence

Actually, the 101 east of the 110 can and should easily go. If the 2 was tunneled south from Elysian valley to the 110 around USC, the 110 and the 101 east of about Vermont avenue could easily be removed. It actually makes a lot of sense. Much of it could be paid for by selling the land to developers, and capacity could be made up for with express lanes along the 5 and new sr2 tunnel.


This reads like an onion article. It’s sad to see all the morons here hailing this as anything but the uninformed, hair brained and idiotic idea that it is.


I think removing I-5 might be a tough sell, but you could mark i-405 as the new i-5, and make i-5 a 3 digit freeway. Under the interstate highway system, the 1 and 2 digit freeways are the mains, and 3 digit freeways are short secondary freeways for local circulation.

So, that would mean practically that the i-5/i-405 intersections would be rebuilt so that through traffic went along the eastside rather than through Seattle. That might require further beefing up I-405, but it’s a lot cheaper to add lanes to I-405 than to add lanes to I-5.

Once I-5 is no longer the main freeway for through traffic, it would be at least possible to discuss turning it into a state route similar to SR-99. That maybe allow things like stop lights and intersections in downtown and some improvement of the street grid.

I doubt you can touch it so longer as it’s a 1 digit freeway though, since deleting a segment would mean breaking the interstate grid.

Roro Secondus

405 would need another lane or two each way.

I5 should remain as a tollway with only two lanes each way and no exits between 520 and I90.

Put it in a covered trench if possible.


Simply burying I5 as a downtown bypass basically duplicates the 99 tunnel. I don’t think Seattle needs two buried freeways to get through downtown.

Roro Secondus

99 is a highway, not a freeway. It has stop lights, etc in most of its course in Seattle (City of). It is not easily accessed from I5 anywhere in town.

As it presently exists, it would not be a suitable substitute for *in city* through traffic.

Additionally, the 99 tunnel is not buried, it was dug at great expense. A cut and cover tunnel would be far less expensive. Usually, the fatal drawback of cut and cover is the disruption it causes on the surface. However, in this instance, the surface would be the unused void where I5 once stood.

Once a given portion of the tunnel is complete, time to restore street grids and build housing on top.

Roro Secondus

Again, I emphasize it should have no exits/entrances between 520 and 90 and should be a tollway.


405 in great shape? Have you driven 405 lately? It’s not unusual for me to spend an hour plus driving from Redmond to Lynnwood at 4 PM. The congestion is terrible, and the toll lanes have only made it worse. Diverting traffic onto 405 would make my life (and the life of many commuters who can no longer afford to live near the places they work) miserable.


Yes, the 405 roadway itself is in “more solid shape” — if you just ignore all the traffic.


Presumably any removal of I5 would include significant mitigation work along the 405 corridor. I’m a big fan of 405 BRT, but the BRT lines could easily grid to a halt with all the extra traffic on 405, even with additional lanes. There would need to be either bus lanes distinct from the HOT lanes or the BRT upgraded to LRT.

A massive reorganization of highway transportation infrastructure will need to include a fresh investment in transit. A “ST4” package could be built around mitigating the removal of I5, investing in things like rail from Burien to Bellevue & Kirkland to Lynnwood.


Luckily, no longer having I-5 could provide huge amounts of land for urban residential development, in theory reducing the price of urban and suburban homes. But if you drive 30 miles from one side of the city to the other there are likely already affordable options closer to your work or similar jobs closer to your home…


405 in solid shape..apparently Doug’s world is pretty small.
Actually Seattle needs I5 as much as Tukwila, Seatac, Shoreline etc.
The need to effectively support commerce outweighs this well presented offering, and facts
Your fantasy theory doesn’t go far enough, with this line of thinking the I90 and 520 bridges should be torn down as well..We don’t need no stinking eggs, milk, food! We have a restaurant right downstairs!
Commerce is the #2 reason the national interstate system was constructed, and it is the #1 reason it still exists today.
I5 still only has 2 full time northbound lanes every morning (since the 60’s construction) and that along with all other issues would be somewhat alleviated by tearing down the convention center and punching 4-5 active lanes both directions thru the city by adding and elevated freeway.
It’s an Interstate people, and it needs to be upgraded and it should have happened 30 yrs ago..
I am retired, do not have to deal with ever going to Seattle ‘cept for visits to the VA and the occasional ball game.
My opinion is based on driving to all points in western Wa day and night since the 70’s and there has been an unbelievable lack of foresight concerning commerce transportation since then by DOT, Every Seattle city council, and the me generation.
A prime example is Sound Transit which was sold to the minions bragging that I5 traffic would be supported with rail from Everett to Tacoma.
Then came lines to other neighborhoods in Seattle, blatantly ignoring the I5 debacle.
Maybe instead Doug should be sending grumpy letters to Sound Transit about I5 instead of turning Seattle into a very hungry island.

Just my 2 bits.


This is an excellent idea, really deserves more consideration. Really hard for most people to conceptualize though. Bulk of industrial and transport destinations are elsewhere in the region (other than direct port traffic). Politically this would be amazing with the rest of the state and maybe even Canada freaking out.


405 in solid shape? Have you ever driven on that thing during rush hour? Here since 2014 and you are confident that removing the main N/S thorough fare wouldn’t affect local commerce that much? I don’t disagree that this is a cool idea, but we would have to have transit with double the capacity or more to make up for it. Even with the freeways available to get to SODO stadiums transit is still overwhelmed on game days


Getting distracted by the particulars – on the south side of the city, it seems pretty straightforward – the exits to Edgar Martinez, 4th, and Dearborn would all likely stay, and I5 north would simply curve directly into I90 East (and vice versa). The urban grid as-is should be able to handle the traffic coming off of the freeway. It will be important for the Port of Seattle to feel it can still move freight effectively on to I90 and I5.

The north side of the city is much trickier. Connecting I5 to 520 is likely a necessity, but do you put an exit between NE 45th on I5 and Montlake on 520? Or do you make anyone trying to get to downtown exit at 45th and take Eastlake all the way in? Without bus lanes, Eastlake would immediately become unusable for transit.


Consider transit coming into Seattle from 520 – how will those buses get downtown?


No, exiting all 520 buses to Husky Stadium for transfer to Link; that’s not an option. When North Link is built out to Lynnwood, those trains will be full when they arrive at UW Station. No room for buses-ful of transferring eastside riders.


There’s a maximum thru-put of trains on a single track, in the range of 20-25 per hour, so you can’t just “add more trains!” when that capacity is reached. Yes, riders will be getting off at U District and UW stations, and thousands of local riders will be getting on — many by transferring from local feeder buses serving north and northeast Seattle.
My point remains — you can’t take a dozen eastside bus routes and just dump all their riders at Husky Stadium. There will not be room for them on that single Link route. If you don’t believe me, then please talk to planners at Sound Transit and inform yourself.


Under the current system, yes. But removal of I5 should happen in a post ST3 world, where a 2nd downtown tunnel should allow significantly more trains passing through UW station, plus a full Link & BRT network on the east side funneling riders onto East Link.

If 520 is really that critical for transit, then build a 2nd Lake Washington rail crossing as a part of any I5 remove project:

It’s not like WSDOT would just remove I5 without giving ST and SDOT a few years of a heads-up to plan for it…


“…should allow significantly more trains passing through UW station…” But only if you build a second trackway through that station.

My final comment here: The proposal to remove X miles of I-5 through Seattle needs to be shelved, and perhaps pulled off every April First for a few chuckles.

Stephen Fesler

There are indeed capacity constraints. Maximum trains per hour is just one. Sound Transit can up the number of connected train units as well. The platforms have capacity for more than just three-car trains. It seems very unlikely that we are close to being at risk of exceeding actual capacity even if you terminated ever cross-lake route at UWS.


Link platforms can accommodate 4-car trains, and nothing longer. The long-term operations plan for North Link already assumes all 4-car trains all the time — and that those trains will be full during rush hours. So no, we can’t plan on terminating cross-lake bus routes (SR-520) at UW Station. Like I suggested to Doug T., check with Sound Transit to verify.


There are issues with this proposal, but the capacity of Link is not one of them: https://www.seattletransitblog.com/2015/03/21/capacity-limitations-of-link/
In all likelihood the 520 buses will stop going downtown as soon as they figure out the best way to connect 520 with the Husky Stadium Station.


Exit at Mercer?


Yeah, that would be the other option.


Removing the freeway downtown also yield a trench that would function quite nicely as the 2nd downtown tunnel for a significant stretch of downtown – that could chalk up nearly $1B of additional savings.

I would strongly object characterizing 405 as “pretty solid shape” – 405 between Bellevue & 167 is gridlocked every afternoon. A new HOT lane is funded & another GP lane is planned but unfunded, but that’s only until 405. Any remove of 405 would require a major expansion of 405 between I5 & 167 simply to handle the through traffic.

I think removing I5 is a great idea, especially in the face of a massive rebuilding expense. However, WSDOT will still have to spend billions on 405. Perhaps building a “freight only” lane along 405 would alleviate many of the objections coming from the Port, Boeing, or other manufacturing interests that depend on I5?


I think he means that I-405 physically is in good shape. Traffic is terrible, but that is a different matter. I would also assume that adding additional (HOV, HOT or bus) lanes along there would be cheaper than expanding I-5.



Matt the Engineer

I love this.