All posts by Matt Gangemi

There was recently a Grist article about Andrew Thaler’s easy technique to visualize sea level rise.  His maps show the near complete loss of some cities with the worst-case 80m sea level rise.  This is roughly the level at which the Greenland and Antarctic ice sheets have completely melted, along with the world’s glaciers. I’m not a climate scientist, but WUnderground has a good description of the current (3.1mm/yr) and predicted future sea level rise.  They describe the IPCC’s prediction for “most likely” rises of 0.8 to 2 m by 2100.  I include this to say the 80m level is a long, long time from now and only if things go terribly wrong.  But for entertainment purposes, here is Seattle at 80m sea rise, with more after the jump:

Boeing Field no longer looks like the best use of land.

Continue reading “Seattle with an 80m Sea Level Rise”

Earlier today Frank posted an article about designing cities to help serve women and their transportation needs.  I thought I’d take a look at numbers for Seattle’s current mode splits.  All numbers are from the 2012 American Community Survey, and the percentages you see are the total number of commuters of a given mode and gender over the total number of commuters of any mode in that gender.

First, let’s look at the similarities.  There are similar numbers of commuters overall, with only 7% more male commuters than female (189,929M, 176,274F).  Male and female Seattleites drive in almost identical proportions (49.3%M, vs. 49.2%F).  They walk to work in similar proportions (10.1%M, 9.7%F), and work at home in similar ratios (7.2%M, 6.8%F).  But when we start looking at transit, the numbers start diverging.

Looking at “public transportation” as a group, women are well ahead of men (21.5%F, 18%M), and they keep this advantage when looking at buses in particular (20.5%F, 17.4%M) and “subway or elevated” (0.5%F, 0.3%M).  Even carpools have women leading men (9%F, 8%M).

Where men lead in alternative commutes is bicycling (5.6%M, 2.5%F) and taxis (1.8%M, 1.3%F).

Of course, one weakness of the ACS is that it only tries to capture commutes.  Like Vienna, it seems common in Seattle to have traditional gender roles of women running more errands than men, which might explain the 7% difference in number of commuters.  I’d love to see a study here that captures all trips, not just commutes.

As an aside, I’ve always found it interesting that our STB meetups seem to have many more men than women, and all of our regular writers here are men.  Considering women dominate Seattle’s transit scene, it’s strange that we’re missing out on the female perspective or even a female voice.  If you have something to contribute, send it to us at contact@seattletransitblog.wpcomstaging.com.

Living in the Seattle area means having access to nature, even by bus.  There are blueberry farms you can ride to, hiking trails, and recently I discovered a campground with a bus stop at the entrance.

King County’s Tolt MacDonald Park is unlike any campground I’ve experienced.  It’s very close to the Seattle area, and just outside the city limits of Carnation.  From the campsite it’s a 13 minute walk to the grocery store, complete with Starbucks.  I wouldn’t be surprised if pizza delivery was available. Continue reading “Camping by Bus: Tolt MacDonald Park”

Last year King County tried out a new technology for the first time on US soil in Ballard. It’s called a Vertical Shaft Machine (VSM), and it’s a little like a Tunnel Boring Machine (TBM), but gravity makes the process easier. A TBM is a complicated machine that bores horizontally, pushing its way forward, carrying dirt out the side, and carrying concrete sections in. A VSM, however, can remove soil using a pumped water slurry. Also, concrete sections are simply added to the top, dropping down as the machine digs deeper. This results in a much simpler operation than a TBM, yet one that’s faster, safer, and requires a smaller footprint than traditional shaft construction. King County Project Representative Marty Noble says “In the 35 years I’ve been in this business I’ve never seen a shaft constructed in such difficult soil and ground water conditions and turn out as well as this one.” He says that caisson shafts are normally limited to 60-70 feet in depth but the VSM shaft was 150 deep and is “the best looking shaft I have ever seen.”

The Ballard shaft was only 9 meters wide, but could such a technology be used for building subway tunnels? The shaft built to reach the Beacon Hill station was 15 meters wide. Sebastian Berblinger of Herrenknecht, the maker of King County’s VSM, says that they currently build 16 meter wide VSM’s and have plans for up to 33 meter VSMs in the research and development stage. Sebastian tells me that a 16 meter wide VSM can generally build an 85 meter deep shaft, which would more than cover the depth we’d need for a Queen Anne station (Uptown has an elevation of around 43 meters, and the top of the Counterbalance is around 114 meters). And it could build it fast – up to 5 meters deep per work shift. VSMs have been used to build subway lines in Italy, Russia, and a high speed rail line in Spain.

Of course there would be other technical issues with a deep subway station such as elevator speed and capacity. But it’s encouraging that this new technology has the potential to make the physical depth of construction a smaller problem.