Does Seattle have long term plans for I-5?

[OCGuy81]

This is an absolute bottleneck, with no room to grow because of the limited space between Lake Washington and Puget Sound. 

Have there ever been any thoughts to doing a tunnel, similar to what they did with Alaskan Way?

[PNWRoadgeek]

Have there ever been any thoughts to doing a tunnel, similar to what they did with Alaskan Way?

I-5 through a small part of downtown is already a tunnel. However, it's 2 separate tunnels and even with a tunnel, I-5 would still have tons of traffic. No one wants office buildings in Seattle demolished just because they want to widen a freeway. It's a bottleneck because it's in a busy area and people are trying to get to places using the freeway. At least the express lanes are mostly through a tunnel, but they only help a little bit.

[hotdogPi]

The I-5 corridor seems to be lacking in good surface alternates other than WA 99. If say, Martin Luther King Jr. Way had more interchanges or simply fewer cross streets, some people who would take I-5 currently would prefer to take the now-faster Martin Luther King Jr Way, which also saves on distance. It's probably too late to fix it now, though.

I assume a wide bypass using the existing WA 16/3 corridor is infeasible?

[Bruce]

This is an absolute bottleneck, with no room to grow because of the limited space between Lake Washington and Puget Sound. 

Have there ever been any thoughts to doing a tunnel, similar to what they did with Alaskan Way?

Seattle, being an isthmus, will always have transportation bottlenecks. Building expensive new freeways that will immediately clog and attract more traffic would be pointless and ruin swaths of the city. The long-term plan is to get as many people onto grade-separated transit (Link light rail) and buses for in-city travel and route through-travelers around on I-405.

I-5 will be seeing major construction in the next few years, but it'll be a long-overdue resurfacing project that goes all the way up to Northgate. It's being put on hold until the light rail extension in Lynnwood opens, since buses would be feeding it to get people away from the freeway.

The I-5 corridor seems to be lacking in good surface alternates other than WA 99. If say, Martin Luther King Jr. Way had more interchanges or simply fewer cross streets, some people who would take I-5 currently would prefer to take the now-faster Martin Luther King Jr Way, which also saves on distance. It's probably too late to fix it now, though.

I assume a wide bypass using the existing WA 16/3 corridor is infeasible?

MLK Way was the corridor for the RH Thomson Expressway, which would have wiped out Seattle's largest Black neighborhood. It was cancelled thanks to outcry from multiple neighborhoods and groups from across the spectrum, so it's safe to say it would be downright suicidal to propose today. SR 16/3 makes no sense as a bypass since it would require a ferry ride (or two) at the north end, which eats up any time savings this theoretical freeway would have. A cross-Sound bridge wouldn't be feasible unless we can invent something that can meet all the needs (not $1 trillion, high enough for cargo ships, low enough to not need giant approaches, possibly floating due to the depth of the Sound).

I-5 isn't that bad as long as you don't drive during peak of peak or in the reverse of the express lanes during peak hours. Just plan smartly and you can avoid congestion, or wait it out in the city where there's plenty to do.

[Bickendan]

Or you could just do what I did when I went up to Seattle back in March: Drive up WA 99 from Tacoma to Everett

[OCGuy81]

Or you could just do what I did when I went up to Seattle back in March: Drive up WA 99 from Tacoma to Everett

Even getting to WA99 can be a challenge.  I think 5 is bad from Olympia all the way to Everett. 

[Max Rockatansky]

99 as someone who works in Washington but doesn't live there is far less useful than it used to be given the Alaskan Way Tunnel is tolled.  A lot of the SeaTac rental car companies (which unfortunately my employer selects) penalize you for using the tunnel rather than just adding the toll to your agreement final bill. 

[Bickendan]

Or you could just do what I did when I went up to Seattle back in March: Drive up WA 99 from Tacoma to Everett

Even getting to WA99 can be a challenge.  I think 5 is bad from Olympia all the way to Everett. 

I cheated. I took WA 507, 702, and 7 to get around Olympia and JBLM.
Getting through Yelm was annoying.

[Bruce]

If I'm heading south into Seattle at an inopportune time, my go-to move is to take the train from Northgate or leave I-5 near Green Lake and take local streets over to the start of SR 99's expressway section.

If I have to be in Tacoma, I'm not going during rush hour. That's just asking for trouble. Same with trying to travel north from Everett after Boeing's shift change.

[Plutonic Panda]

It needs to be expanded regardless. Traffic won't ever be fixed for peak hours but it can help shorter the rush hour window.

[hotdogPi]

Do we have data on what percentage has its origin and/or destination past the end of the commuter rail line (and therefore can't use it)?

[jakeroot]

Do we have data on what percentage has its origin and/or destination past the end of the commuter rail line (and therefore can't use it)?

Typically in these cases, the passenger will use another mode of transport to access the rail line. Buses are probably the most popular option. Park and Rides as well.

It needs to be expanded regardless. Traffic won't ever be fixed for peak hours but it can help shorter the rush hour window.

I don't think there is much political support for this. I think more people would like to see Seattle like Tokyo: no traffic congestion, but also 85%+ usage of public transportation.

[Plutonic Panda]

I highly doubt most people that live in Seattle want to see the city become more like Tokyo. But yeah, I would agree there won't be much political support for this.

[Bruce]

It needs to be expanded regardless. Traffic won't ever be fixed for peak hours but it can help shorter the rush hour window.

We could just use a congestion charge. That could fund all sorts of congestion-busting measures and prevent people from unnecessarily traveling during the worst hours. Of course it can't be implemented until we've built out more rail transit, which is slowly but surely happening.

Do we have data on what percentage has its origin and/or destination past the end of the commuter rail line (and therefore can't use it)?

This outdated 2012 Stations Access Study is one resource, but it only looks at a few stations. The numbers for Tacoma Dome are pretty telling, with 77% of arrivals by car; about 63% of a small sample size said they were originating within Tacoma as well.

I highly doubt most people that live in Seattle want to see the city become more like Tokyo. But yeah, I would agree there won't be much political support for this.

The city's voters have been in favor of more transit and density in ballot measures (such as I-135 earlier this year and ST3/Metro Prop 1), even if the politicians elected don't necessarily push it as much as it could. The state now has a wider density-near-transit policy that was adopted by the legislature, so the opposition is very much at the neighborhood level (through design review and other bullshit processes).

This 2019 Times/Elway poll is pretty direct with the question:



Sadly the poll didn't split up the next big questions, so the entire county's results are included. Still indicates majority support for more bus lanes and more streetcar, but not bike lanes and eliminating parking minimums.

[Henry]

The only solution would be to build a double-deck section, as referenced in the OP from the General Highways thread "Double-decking freeways. Where would it make sense?":

* I-5 through Seattle.  Despite dismantling the eyesore that was the Alaskan Way viaduct, it looks like the only option to ever expand capacity on I-5, roughly from the I-90 interchange to the Northgate area, would be to double deck.

While I agree with this idea, I don't think Seattleites would feel the same; in fact, they don't want a redux of the Alaskan Way viaduct, even if it is on I-5.

[jay8g]

The chance of I-5 ever being widened anywhere in Seattle, but especially through downtown, is effectively zero. Not only is there no political will, I don't think people on here realize just how insane the cost of that would be. From a political perspective, it would be much more likely to see I-5 removed through downtown (perhaps from I-90 to Mercer or 520), with long-distance traffic rerouted to 405 (which is being widened).

To answer the original question, the current "long-term plan" is to keep I-5 the way it is and maybe install lids over some portions (though the people advocating for that don't seem to have an answer for what to do about the elevated portions, including through the International District). That being said, there's already a lot of maintenance needed on the downtown section that WSDOT doesn't have the money for (because the legislature refuses to fund maintenance), so there may be a point in a few decades where removal becomes a serious consideration.

In this day and age, I don't think the political will to build the SR 99 tunnel even exists anymore -- it's much more likely that the Alaskan Way Viaduct would have simply been removed and the new surface street built the way it is being built now. Hardly anyone uses the tunnel anyway, compared to the Viaduct, since it is tolled.

[vdeane]

Removal of I-5 would seem to me like it would spark a carmageddon scenario.  There are only two north-south freeways in the Seattle metro area, both of them very prone to congestion.

[Bruce]

Removal of I-5 would seem to me like it would spark a carmageddon scenario.  There are only two north-south freeways in the Seattle metro area, both of them very prone to congestion.

Obviously the removal would be paired with appropriate boosts to transit. It's not going to be on the table for a long time.

[Max Rockatansky]

Removal of I-5 would seem to me like it would spark a carmageddon scenario.  There are only two north-south freeways in the Seattle metro area, both of them very prone to congestion.

Obviously the removal would be paired with appropriate boosts to transit. It's not going to be on the table for a long time.

There is no amount of transit that would cover the loss of I-5 through downtown.   Things are bad as is with just having WA 99, I-5 and I-405 as the only through routes available in the Seattle metro area.  The downtown surface streets have become only increasingly hostile to through traffic attempts over the years also.  There is just plain not enough north/south carrying capacity in the Seattle area for everyone as is.  I'm not saying that I have a solution, I just don't see totally removing I-5 and trying to patch it with transit as one.  Keeping I-5 and ramping up future transit efforts sure seems like a more viable solution/mitigation.

[Bruce]

Removal of I-5 would seem to me like it would spark a carmageddon scenario.  There are only two north-south freeways in the Seattle metro area, both of them very prone to congestion.

Obviously the removal would be paired with appropriate boosts to transit. It's not going to be on the table for a long time.

There is no amount of transit that would cover the loss of I-5 through downtown.   Things are bad as is with just having WA 99, I-5 and I-405 as the only through routes available in the Seattle metro area.  The downtown surface streets have become only increasingly hostile to through traffic attempts over the years also.  There is just plain not enough north/south carrying capacity in the Seattle area for everyone as is.  I'm not saying that I have a solution, I just don't see totally removing I-5 and trying to patch it with transit as one.  Keeping I-5 and ramping up future transit efforts sure seems like a more viable solution/mitigation.

The downtown section is nearing the end of its useful life. When the bill for the inevitable rebuild gets presented, there will be a lot of resistance to paying for it.

I'm not a believer in the current, fantastical proposals to remove I-5, but there are alternatives out there. Just need to look a bit north to Vancouver and what they do right/wrong with flow without downtown freeways, for example.

[jakeroot]

I'm not a believer in the current, fantastical proposals to remove I-5, but there are alternatives out there. Just need to look a bit north to Vancouver and what they do right/wrong with flow without downtown freeways, for example.

I would caution against too much comparison to Vancouver, they have a gridded arterial roadway network more like Los Angeles than Seattle, with four to six lane arterial roads all over the place. There are no through-freeways but there are plenty of huge roads with crazy-long pedestrian crossings. Vancouver is also a traffic peninsula with little demand for travel west or north of Vancouver, except to ferries and the Sea to Sky. Seattle is the in the middle of numerous populated areas with cross-city travel being very common.

[Max Rockatansky]

I can't help but feel that as time goes on and the rebuild for I-5 comes up there is a strong chance that urban freeways won't be the "villain of the month" anymore.  There is a huge urbanist drive against existing urban freeways right now.  Trouble is that those urbanists aren't really offering much in the way of actual alternative solutions other than "forced transit."  If/when the prospect of screwing over the majority of urban commuters in/through downtown Seattle by removing I-5 starts to actually be discussed it likely will die a quick death due to public/political backlash.  I-5 isn't a duplicate corridor like the Harbor Drive Freeway in Portland was. 

[Plutonic Panda]

^^^ yup that's exactly my thoughts as well.

[The Ghostbuster]

Could Interstate 5's express lanes be converted to congestion-priced toll lanes? Since Interstate 405 now has express toll lanes, maybe 5's express lanes could be converted as well.

[Bruce]

Could Interstate 5's express lanes be converted to congestion-priced toll lanes? Since Interstate 405 now has express toll lanes, maybe 5's express lanes could be converted as well.

WSDOT studied a conversion back in 2011. Predicted outcomes were that 22% of traffic already using the express lane would shift to another way (likely the mainline) and that peak-direction speeds would increase at the expense of "reverse" direction commuters (often workers from the Eastside returning to Seattle in the afternoon). Overall, not worth it in their eyes.

The express lanes should have been converted to a bi-directional busway decades ago, but that role is basically being carried by light rail expansion to the north anyway. Maybe we can re-use it as an express rail ROW when the time comes to replace the unreliable coastal route for the Scenic Subdivision.

This study was mentioned in this 2017 Seattle Times article discussing possible improvements, including the new mainline lane that was completed last week.