What City Observatory did this week

The case against the Interstate Bridge Project.  We offer 16 reasons why Oregon and Washington lawmakers should question the current plans for the proposed $7.5 billion I-5 freeway expansion project between Portland and Vancouver.  Here’s reason #10 (but click through to read all 16!)

10.  IBR traffic projections have been proven dramatically wrong:  They grossly over-estimate future traffic levels on the existing bridge, which is capacity constrained.  The CRC FEIS predicted I-5 traffic growth of 1.3 percent per year; actual growth was 0.3 percent per year through 2019. They also fail to accurately predict future traffic levels.  The independent Investment Grade Analysis in 2013 showed that the IBR forecasts overstated future I-5 traffic levels by about 80,000 vehicles per day, leading to the design of a grossly over-sized project.


Put a bird on it:  Greenwashing highway expansions.  State highway agencies have their own carefully crafted logo for a program called “Planning and Environmental Linkages” which promises more environmentally friendly highway projects.  But when you look closely at what PEL actually entails, it’s clearly all performative process, with no substantive requirements.

As long as a highway intones gravely about the environment, it can do pretty much whatever it wants.  Case in point, a recent “Planning and Environmental Linkage” report for a major highway in Georgia contains none of the following words:  “climate,” “pollution,” “greenhouse gas,” and “emissions.”  What you will find in the report is a prominent logo, with nary a car or truck to be seen.  Put a bird on it!

Must Read

Just another deadly stroad: How Complete Streets got co-opted.  The indispensable Chuck Marohn is in fine form with a new essay on how highway engineers and road departments have coopted, and largely eviscerated the “Complete Streets” movement.  The concept behind complete streets–that we design our streets to provide safe and equal access to all people, regardless of the mode by which they travel, is sound.  In practice, however, roads that explicitly prioritize faster car movement and endanger cyclists and pedestrians can qualify as “award-winning” complete streets, given a watered down, mindless checklist approach that’s been adopted.

Marohn illustrates this with an example of Ager Road outside Washington DC.  Its literally won awards from professional road building, and engineering groups.  But the “improved” road replete with dangerous design features like slip lanes and too narrow bike lanes that endanger non-auto users. It’s painfully difficult to tell apart the “before” and “after” pictures of the project, because both are so auto-focused.  And the traffic data show that, post “Complete Streets” treatment, still nearly 70 percent of drivers exceed the posted speed limit.  Unsurprisingly, this “complete street” claimed yet another life.

The problem is that the advocates of complete streets essentially sold their souls for to get their branded idea adopted.  Highway agencies and engineers were more than happy to adopted the mantle, and provide congratulatory awards, while gutting the underlying concept, and using it to pretend that they were actually doing something to improve the safety and fairness of the transportation system.  Marohn writes:

Yet, a top-down strategy meant working within entrenched systems. It meant finding common cause with the very people who most fervently resisted their ideals. There was certainly more funding with this approach, along with greater access to power, but the ultimate cost of that success was having the core ideals of Complete Streets cast aside and tokenized.  We need you to wake up, Complete Streets advocates, and recognize that your work is being widely used for evil ends.

Highway engineers have debased and perverted many potentially meaningful terms like “multi-modal” and “pedestrian infrastructure.”  Co-opting complete streets is safety-washing, just as highway departments have engaged in woke-washing with phony equity claims, and green-washing with performative and meaningless “planning and environmental linkages.”

Freeways without futures.  The latest annual installment of the Center for New Urbanism report, Freeways without Futures is now available.  The recent passage of the $1 billion Reconnecting Communities program as part of national infrastructure legislation has given added impetus to community efforts to repair the damage done by urban freeways by a combination of capping, removal, and boulevard conversions.  Here’s a list of this year’s candidates, and we hope this helps hasten their demise, and rebirth as contributors to the urban fabric, instead of destroyers of it.

  • Interstate 787, Albany, New York
  • Interstate 35, Austin, Texas
  • US 40 Expressway, Baltimore, Maryland
  • Interstate 794, Milwaukee, WI
  • State Highway 55/Olson Memorial Highway, Minneapolis, Minnesota
  • Interstate 94, Minneapolis-Saint Paul, Minnesota
  • Interstate 980, Oakland, California
  • State Route 99, Seattle, Washington
  • Interstate 244, Tulsa, Oklahoma
  • US Route 422, Youngstown, Ohio

New Knowledge

Traffic congestion reduces vehicle miles traveled.  We tend to view traffic congestion as an unmitigated bad.  But in the presence of traffic congestion, we change our behavior.  A new study looking closely at travel survey data from the Seattle area shows that people who live in more congested parts of a metro area tend to own fewer vehicles and drive fewer miles.

The study looks at how a broad range of factors (including commonly understood variables like density, design, diversity and destinations (some of the so-called multiple “D” factors influencing travel behavior.  Its core finding is that after controlling for all of these other factors, people who live in more congested areas–as measured by a kind of travel time index computed from Google Maps travel time estimates–tend to drive less than their counterparts in less congested locations.  Specifically, each unit increase in the delay score reduces, the number of household trips  by  16 percent and its total vehicle miles of travel by about 12 percent.

The authors conclude:

. . . travel delay, a measure of congestion, is associated with fewer household vehicles, fewer vehicle trips, and lower VMT. These are beneficial to environment and energy conservation. Congestion might also be seen as an adversary of density because congestion is more likely, though not always, to exist in areas with high density, a key paradox at the center of the land use policy debate. However, congestion can coexist with density as demonstrated by Mondschein and Taylor (2017). While “delay” is treated as a built environment variable in this study, it is a measure of the “mobile” feature of the built environment. This measure differs from other land use density and diversity variables that quantify the “fixed,” long-term features of the built environment. The findings about the effects of travel delay reinforce the notion that travel delay is an important constraint of travel behavior and should be considered along with other “D” factors

In a sense, this is the flip side of our understanding of induced travel.  We know that when we make travel more convenient and faster, vehicle miles traveled increase.  It shouldn’t be a surprise that when an area is more congested, that people respond by driving less. On the surface, that seems to imply that this lessened driving is entirely a sacrifice.  Not necessarily.  Congested places also tend to have more population density and a richer and more varied set of destinations and services.  So even if you drive less, it doesn’t mean that you’re giving up other than the amount of driving you do.  And, just as with induced travel, the implication is that measures that reduce traffic congestion are likely to increase the number of trips people take, and the distance they drive.

This ia particularly important finding for transportation planning. Most existing traffic models assume that traffic congestion influences mode choice or route choice, but has essentially no effect on the number of trips or the number of miles a household drives.  That’s why state DOT travel forecasts routinely predict absurd and impossible levels of traffic growth and congestion.  But as congestion increases, people adapt their behavior, and travel less, taking fewer and shorter trips–something the traditional four step model fails to forecast.

Reza Sardari, Jianling Li and Raha Pouladi, “Delay: The Next “D” Factor in Travel Behavior?” Journal of Planning Education and Research, 2023. https://doi.org/10.1177/0739456X231154001

Hat tip to Michael Brennis at SSTI for flagging this article:  Read his take here.

In the News

Clark County Today republished our commentary, “The Case Against the Interstate Bridge Replacement.”