Washington Roads - WA 99/old US 99 - S. of Alaskan Way

south of Alaskan Way



Remaining US 99 Americana south to the end of WA 99 at 54th Ave. in Fife.


Not enough room for a median leads to half-assed safety measures like a super-wide line in southern Federal Way. It was that or kill the shoulders.


I go from South South to 99 99. I present closeups of 99 99 and wonder where South 99 North is.


WA 99 ends at WA 518 on the north side of Sea-Tac Airport, the south end of the Tukwila decommissioning. There is no trailblazing for WA 99 to get around that gap either, it just stops being.


WA 99 picks up at WA 599 and all is well and good until it picks up the end of WA 509. Actually, it's still well and good, not "TO" 99, and this is the only error of its kind.


WA 99 NB entering the Marginal Way viaduct through the industrial district south of downtown Seattle, up to where the sports teams play. Until 2011, the bi-level Alaskan Way viaduct extended to about where the asphalt turns into concrete in the last photo. The recency of that change (I was there in 2013) may be why there's still construction at the south end of the viaduct. It was done as a precursor to construction of the SR 99 Tunnel to replace the remainder of the 1953 bi-level freeway, which you'll see in a moment, so that the entire highway would be on a single level through Seattle, eliminating the seismically inadequate viaduct.


WA 99 SB from there on the mono-level freeway, at the West Seattle Bridge, in 2004. The way Seattle was constructed, the low-level original city was built up with stonework and then pumped full of dirt to get up to the cliff level. That only goes for downtown, though, where the streets can get mighty steep. Down here, south of the city proper, the cliffs hem WA 99 in along the Puget Sound, while I-5 towers above them, so that there is very little access between the two until much further south.


Your first glimpse of 2013 tunnel construction is NB under the future Colorado Avenue overpass, designed to connect city streets to the south end of the future Alaskan Way surface boulevard (which can be seen in the last 2 photos). The third photo stares straight down the barrel of the tunnel approach, which right now is a mess of cranes and one mean, green, tunnel-boring machine (back right), or TBM.


SB through the same construction.


NB in October 2014, Colorado Ave. is complete and the TBM is underground. I can't say "safely" for reasons I'll explain in a couple of captions.


Check it out, while somehow traveling at freeway speeds: project cost $1.35 billion and completion in December 2015. The final verdict: tunnel opened 2/4/19 with viaduct demolition continuing for months thereafter, final cost around $3.3 billion. Still a walk in the park compared to Boston's Big Dig.


Here's a large section of the future TBM, and a giant rig set up over the southern tunnel portal, probably to stabilize the concrete pouring and/or for whatever is necessary to launch the TBM (named Bertha after a past mayor, but also because she is big) into the future tunnel.


The pièce de résistance is the giant green blade that will chew through the soft muck, hard rock, and at least one unknown steel pipe that will end up causing most of the 39-month delay in tunnel construction. (The machine broke a bearing, overheated, and had to be dug out from above in an extensive 2-year process before being repaired and reinserted.) You can see the tunnel approach walls being poured and stabilized by the white rig, while the TBM will be assembled just shy of the portal to begin its large round bore. Unique to tunnels in the USA, WA 99 was bored as a two-level tunnel, SB over NB, which made the TBM the largest this country has ever seen.


1st Ave. NB gets a new regulatory sign at Royal Brougham Way, requiring the street to the left to be North 99. (A one-piece sign should have a green background here.) Royal Brougham is a person, but I think it works better as a car.

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