Seattle 2035 Transportation Element

Northwest Seattle Mode split expectations Seattle 2035.
Northwest Seattle Mode split expectations Seattle 2035.

A week ago I sat down after work in a Pioneer Square pub with five young men to discuss the Transportation Element and Transportation Appendix of the Draft Environmental Impact Statement for Seattle 2035, Seattle’s Comprehensive Plan for growth over the next 20 years.

These are smart, responsible young men, who were drawn to an off-hours analysis session in part because they are policy wonks, and in part because they feel a deep sense of civic responsibility. Several of them have young children. And these young men are staring down the road at their future, a future they feel responsible for, in a region and a planet that will be vastly different than the place we inhabit today.

I’m setting the context because the realities of the future guided our discussion. We want our city to contribute to a livable planet. We want a city where living without a car is an easy, affordable, and realistic choice.

We came up with four recommendations:

  1. Use a multi-modal, person-trip level of service standard rather than a vehicle level of service.
  2. Count trips, not just commute trips to work.
  3. Make sure Seattle 2035 is in alignment with existing Seattle plans.
  4. Build transportation models that push the envelope rather than following business as usual.

Multimodal Level of Service

Rather than measure and base our transportation network on roadway capacity for vehicle-only level of service, measure the through-put of people – walking, riding buses and trains, in delivery vehicles, riding bikes, driving cars. The metrics we set for “person-trips” will help us fund and build the complete networks we want in the future. Nearby Bellingham and Bellevue have great models for us to study.

Modal share by urban village.
Modal share by urban village.

Commute trips

We’re changing how we work and we often work from home. Our trip to work represents only a fraction of where we travel. We go to schools, parks, bars, and out to visit friends. The Puget Sound Regional Council collected fine-grained analysis of different trips we make during the day. Let’s make sure our 20-year transportation planning models reflect the variety of places and ways we travel as well.

Align with existing plans

We’re especially happy that the Climate Action Plan expects just 25% of us to drive to work alone by 2035 (could we do even better?) and expects transit boardings to increase by 37% by 2040. We’d like to see Seattle 2035 be clear about which plan alternatives greatly increase the possibility we’ll reach our goals for Vision Zero, the Climate Action Plan, transit, and active transportation modal plans. The current DEIS for the Comprehensive Plan assumes Seattle’s walk/bike/transit plans will fail by projecting mode shares that don’t change very much from existing conditions. This is flat-out wrong. According to our mode plans we will be walking, biking, and riding transit a whole lot more in 2035 — and our Comprehensive Plan needs to reflect this welcome reality.

Great models that push the envelope

What kinds of land use plans would inspire developers to be motivated to build properties that minimize auto trips? How can levels of service be used to fund multi-modal street improvements? What would a car-free downtown look like? What would happen if the city no longer subsidized free parking? We encourage the City to make one “visionary” alternative of Seattle 2035 that reflects new assumptions for the trips we make and that dramatically reduces our greenhouse gas emissions.

After a beer (and a soda for the gluten-free young man), and a long discussion, and a flurry of emails, we still feel a deep sense of responsibility to our future city, and a desire to support Seattle government as it plans for our common future. We look forward to living in a great city in 2035!

We’re down to the final 24 hours to comment on the Draft Environmental Impact Statement (DEIS) of the Seattle 2035 plan! Deadline is Thursday June 18. Make your comments in this form or send mail to

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Cathy Tuttle (Guest Contributor)

Seattle Neighborhood Greenways is a safe streets advocacy organization with a rapidly growing volunteer coalition. Together, this coalition represents many neighborhoods across Seattle who plan and advocate for safe, equitable, and comfortable streets connecting people to the places they want to go.

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Tiering from what Cathy wrote, I concur that movement towards measuring people as opposed to vehicles is long overdue throughout the transportation industry. California is on its way with the passage and current implementation process of SB745 which was passed in October 2014 and prohibits the use of vehicle delay (and LOS) as a measure of environmental impact.

Many of the alternative measures studied in California as a replacement to Auto LOS/delay relate to Vehicle Miles Travelled (VMT) – and in particular how to make the most efficient use of each Vehicle Mile that we put out on the network. My personal favorite way to measure this is at various geographic aggregations (on a street, across a screenline, for a specific geographic area) is VMT/Person Trip. How many people are you getting where they need to go for each VMT. Making the most efficient use of each vehicle on our roadways will in turn reduce congestion and improve safety and air quality. The Transportation Element gets part of the way there by analyzing VMT/capita; however, that measure is really only meaningful regionwide.

I will caution against the use of the strict TRB/ITE definition of Multi-modal Level of Service – which is good in intent, but in practice the equations that they use can lead engineers to do things like widen intersections in order to “improve bicycle level of service”.

To wrap up this round of my comments, I strongly recommend that Seattle plan for the reality they want rather than just running away from the impacts they don’t want. Seattle should be planning for the mode share and urban environment that they city WANTS to have and then work backwards to figure out “what it will take” to have it in terms of bike lanes, transit capacity, etc. I understand why the the volume/capacity target for some screenlines is 1.2 (so they never trigger a congestion-related impact and don’t have to mitigate by adding auto lanes); however, that number is completely useless in reality. 1.2 is physically unachievable/unobservable in real life. Rather, I would like to see the city adopt a strategy to figuring out “how many people do we need to get on their bikes by 2030….2020….2018” and “if we grow by X00,000 people, how many of them do we need to ride transit every day to work…how many busses/trains do we need to get online and by when?”.

Just my 2 cents with the major caveat that I don’t think I quite understand the purpose of this document (see below)


You should come by one of our meetups if you ever have the opportunity. Stephen, a planner for Snohomish county, typically attends and can talk in detail about the purposes and impacts of the 2035 plan. Perhaps he’ll respond here or point you in the right direction…


I have come down to the wire on the comment period – but not for lack of attention or diligent study. Rather, I am struggling (as an admitted newcomer) to understand the meat of “what is being decided” in this EIS. At first, I just thought it was just variations on zoning (since that is what seems to be different in the four future alternatives). However, there is reference in the text to this document also defining significance standards (where are these standards evaluated?) and street prioritization – which seems to fit more with what Cathy was commenting on. Any direction on where these things are actually proposed and evaluated would be much appreciated (and again, apologies for what is probably an obvious answer).

Alon Bassok

I support all of the four recommendations Cathy calls for. We especially need to think of movements for families and movements around schools. We need to think outside of the norm. I had the great benefit of working with Cathy on the bicycle urbanism symposium where we pushed for a new paradigm–a city that gives options for everyone to do as they wish to get around, with architecture and design that supports them. Keep pushing Cathy. You do great work.

Megan Horst

I completely agree with these four recommendations! Thank you all for analyzing this. I see the sentiment (and think it can be articulated even more loudly and clearly in this post) that we should be planning for MUCH lower rates of drive alone travel in Seattle 2035- of course, backed up by the needed transit/bike/walking investments and land use planning. I look at the plans for NW Seattle, and see barely any expected changes in mode share or VMT. This is unacceptable for a city and neighborhood growing so rapidly and supposed to be aiming for carbon neutrality. The Comp Plan needs to not plan for business as usual, and plan for more significant changes in how we get around.As for specifics, I don’t understand the last two sentences (or their implications) in the “Align with existing plans” section of this post? Also, I agree we need more models and you came up with some great questions to model. Are there any examples where such models have been developed and applied? But, I admit I am not a transportation planner, so hoping my transportation geek friends can chime in. Maybe City Council Candidate for Position #9 Alon Bassok wants to weigh in?

Fred Miller

Commuting is “only a fraction” of transportation, but it’s a pretty big fraction. Commute decisions are made by workers when they accept a job, but also by employers when they hire. So far, employers have had almost no responsibility for the consequences of their hiring and transfer decisions on our traffic, air quality, and communities.

Two examples: A friend works for PCC. He started at the Green Lake store, where he could walk or bike easily. Then he was transferred to Issaquah. Another friend was hired by Boeing in Everett. He bought a house four miles from Paine Field. Five years later, he was transferred to Renton. The employers don’t pay the commuter for driving to work, or for fuel consumed. They don’t pay extra taxes to pay for the extra roads needed to move their workers around. THey have no reason to consider the cost of commuting.

A modest tax on commuting would get employers’ attention, and motivate them to hire locally or to help employees move close. It could be set up as a “feebate”, where revenues collected are returned to employers who hire locally, meaning no net increase intaxes. Reducing miles travelled costs less than getting drivers into mass transit, is better for the air and the climate, and supports vibrant communities.