space traveling warriors tier list : WSDOT ignores actual weather analysis in its road system plan update

The Washington State Department of Transportation is updating its Highway System Plan, but is failing to submit alternatives to actual climate analysis. (Photo: WSDOT)

The Washington State Department of Transportation (WSDOT) is in the process of updating its Highway System Plan now. Updated every decade, the HSP outlines the agency’s broad priorities on how to maintain and improve the state road network, and what’s in the plan has direct implications for what the WSDOT will present in its budget request to the governor and state legislature. However, despite the formalization recognition by the state government of the need to reduce greenhouse gas emissions, the current HSP update appears to lack a substantive analysis of its climate impacts.

In April, the urbanist covered how the agency is gathering feedback on the plan through a flawed survey that lets users choose how to prioritize money in the highway budget, but that doesn’t allow them to spend less than $800 million a year on new and expansion. of road infrastructure.

The agency is now advancing three scenarios for further analysis as it prepares to finalize the plan later this year.

One is a “keep and innovate” scenario that increases the cost of maintaining current highways and assumes that new and expanded highways would only be financed at the level they are now receiving. In this scenario, the agency would spend more resources than it has spent in the past on active transport, transport demand management, and security improvements.

A second, “maintain and expand” scenario just spends additional money on both maintenance and expanded highways.

A third scenario, dubbed “a little bit of everything”, tries to add some additional funding to every possible category, including security, active transport, maintenance and expansion. None of the three scenarios analyzed include spending less than $10 billion on new and expanded highways over the next two decades, despite transportation being the biggest source of greenhouse gas emissions in Washington.

A graph showing the no change alternative with three alternatives going to $70 billion in 20 years as described
Three alternative scenarios for the next two decades are being analyzed as part of the road system plan. All three assume additional billions spent on expanded highways. (Credit: WSDOT)

In May, WSDOT presented to the Washington Transportation Commission its analysis of the three scenarios, showing how it had completed each scenario performed on several different metrics. The “a little bit of everything” proposal had the worst score in almost all of them, including maintenance monitoring.

A graph showing steady results for the maintenance and innovation and maintenance and expansion scenarios and poor results for the little-everything scenarios
Analysis conducted by WSDOT rated their “a little bit of everything” scenario low on most metrics, but found that the “keep and innovate” and “keep and expand” scenarios performed better. (Credit: WSDOT)

But when it comes to analyzing the environmental impact of these scenarios, things go awry. The WSDOT told the commission that its initial analysis concluded that the three scenarios had essentially the same impact on the state’s greenhouse gas emissions. In other words, according to the WSDOT, spending $10 billion on expanded highways (in the “keep and innovate” scenario) would have exactly the same impact as spending more than twice that amount (in the “keep and expand” scenario).

A green checkmark for all scenarios studied by the WSDOT as described

This surprising fact was noted by Hester Serebrin, transportation commissioner and policy director at the Transportation Choices Coalition, who asked how “a major investment in expansion gets a green check in terms of GHG, given what we know about induced demand”. established fact that adding additional road capacity in places where there is high demand will lead to more driving.

“I don’t think there’s a high degree of confidence in this answer right now, but just [the modeling group’s] preliminary sensitivity tests, they’re not seeing a big difference… for now, that’s the best information they can give us,” replied Karena Houser, WSDOT’s state planning manager. “There are other things that are driving GHG emissions more than how we spent the money, on the infrastructure choices we had in our scenario,” she said.

Urbanist followed up by email with WSDOT Acting Director of Communications Emily Glad, who reiterated that a more in-depth analysis of the impacts of greenhouse gas emissions is planned. But she has largely championed the idea that project-level emissions have little impact.

“WSDOT policy requires addressing greenhouse gas emissions and climate change at the project level,” Glad wrote. “WSDOT believes that GHG emissions are a matter of global concern. In our work to date, we have found that greenhouse gas emissions from a single project action are often very small (and often lower than without the project). In general, project-level actions that can help reduce greenhouse gas emissions include: expanding transit and non-motorized options for commuters, improving the flow of intersection traffic to reduce idleness, creating a safer and more efficient loading and increase vegetation density relative to pre-project conditions to sequester carbon”.

Here Glad extracts an often-used argument in favor of road expansion: that additional lanes will decrease the number of vehicles idling and therefore decrease emissions. Data shows that stop-and-go traffic, as well as vehicles traveling at speeds below 40 miles per hour or above 60 miles per hour, result in higher emissions per mile traveled. However, when it comes to emissions, the amount of vehicle miles traveled (VMT) and the vehicle’s fuel efficiency have a more significant impact than speed.

In fact, one 2012 study conducted by Portland State University researchers concluded that there was no correlation between congestion levels in a metropolitan area and per capita greenhouse emissions, while the amount of VMT in a region was strongly correlated with emissions.

“Capacity expansions that reduce marginal emissions rates by increasing travel speeds are likely to increase total emissions in the long run through induced demand,” concluded Alex Bigazzi and Miguel Figliozzi, authors of the paper. the urbanist We’ve included the myth of expanding roads to reduce greenhouse gas emissions in our list of five big untruths that are delaying climate action.

However, the WSDOT also told the transport commission that it concluded that the scenarios are exactly the same in terms of the amount of VMT per person, another fact that illustrates the lack of rigorous analysis being conducted around the plan.

Graph showing an arrow that remains flat in all scenarios
WSDOT analysis surprisingly shows no impact on vehicle miles traveled under any of the twenty-year spending plan scenarios. (Credit: WSDOT)

In late 2021, WSDOT released a initial report on how the state could set targets to reduce VMT and set localities to achieve those targets. The WSDOT report itself undermines the claim that expanded highways would have little impact on VMT. “The potential expansion of highways, as opposed to other transport investments, often increases vehicle travel miles, making access to more distant lands more attractive than previously,” the report states. “On the other hand, investing in efficient transportation communities can reduce vehicle miles traveled by locating people closer to the activities they want to engage in and providing transportation options beyond driving alone.”

To give Washington residents a better idea of ​​how their tax dollars might be invested in transportation, the HSP update should clearly provide an alternative model that shows what it would mean for the state to invest that additional ten billion dollars in other transportation options. transport, such as transit and active transport, as well as studying a no-build alternative that looks at zero additional dollars spent on road expansion. These models must be accompanied by a more rigorous analysis of the greenhouse gas emissions of all models. Such an approach would provide greater honesty and transparency around the impacts of emissions.

As states like Colorado moving forward to quantify and reduce project-level emissions from road expansions, to see this insufficient level of WSDOT analysis around a plan that will guide investments over the next 20 years is extremely disappointing. It is past time the WSDOT stopped burying its head in the sand and did an honest analysis of the climate impacts of continuing to expand the state road network.


senior editor

Ryan Packer lives in the Summit Slope neighborhood of Capitol Hill and has written for the the urbanist since 2015. They report on issues of multimodal transport, #VisionZero, preservation and local politics. They believe in using Seattle’s history to help achieve the vibrant and diverse city we all want to inhabit. Ryan’s writing appeared in Seattle Capitol blog, Portland bikeand Seattle bike blogwhere they also spent four months as a temporary editor.

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