Ignoring Induced Demand is Engineering Malpractice

In 2022, denying how highway expansions induce people to drive more should be considered professional malpractice.

#NoNewRoads, Engineering Profession, Marohn, Transportation, Top StoryCharles MarohnApril 4, 2022transportation, transportation spending, highways, freeways, Virginia, engineers, engineering ethics, engineering profession, traffic engineering, traffic projections, induced demand, #NoNewRoads

Why Do We Have to Handle 30,000 Trips per Day?

When engineers say a street must accommodate a high volume of traffic, what they really mean is, "The design of this street must prioritize the convenience of commuters over all else."

Jarrett Walker: "Prediction and Freedom Are Opposites"

Special guest Jarrett Walker shares his thoughts on the limitations of prediction.

ST Podcast, Transportation, Planning Profession, Podcast, Public Transit, Top StoryStrong TownsJanuary 24, 2022Podcast, podcast, Jarrett Walker, projections, traffic projections, transit, public transit, public transportation, planning profession, planning process, urban planning

More Highways, More Driving, More Emissions

Fact: New roads always produce new driving. Say hello to “induced demand.”

10 Reasons to Not Trust ODOT's Environmental Claims

Oregon’s Department of Transportation is making phony claims that widening highways reduces pollution. Here’s why they’re wrong.

All Traffic Models Are Wrong

Traffic engineers use projections of future traffic to make recommendations and decisions on transportation investments… The problem is, those projections are all wrong.

#InfrastructureCrisis, #NoNewRoads, Confessions Book, Engineering Profession, Infrastructure, Marohn, Transportation, Top StoryCharles MarohnSeptember 7, 2021traffic projections, traffic engineering, Confessions of a Recovering Engineer, confessions book, engineering profession, Infrastructure, confessions excerpt

The Projections Fallacy

We spend billions every year on our transportation network, large percentages of it based on traffic projections—despite the fact that we don’t accurately project traffic.

Engineering Profession, Mistakes A Town Makes, Roads and Streets, Marohn, Transportation, Top StoryCharles MarohnAugust 16, 2021traffic projections, traffic congestion, engineers, engineering profession, transportation, traffic engineering

Carpocalypse Never?

Why do predictions of “Carmageddon” so often fail to materialize? Recent lane reductions on a major bridge in Portland may hold answers, if we pay attention.

City Observatory, TransportationStrong TownsSeptember 30, 2020traffic congestion, traffic projections, Portland OR, Joe Cortright, City Observatory

A Reminder for Planners: "Every Projection is Wrong"

Put away the Excel sheet and go for a long walk.

Herriges, Planning Profession, The Infrastructure Cult, Top StoryDaniel HerrigesMarch 3, 2020infrastructure cult, traffic projections, projections, urban planning, planning profession

Car-pocalypse Not Now: Why Predicted Gridlock in Seattle Was (Again) a No-Show

Why are we still surprised when a highway closes and fears of traffic pandemonium don’t come to pass?

Top Story, Transportation, HerrigesDaniel HerrigesJanuary 31, 2019induced demand, traffic projections, congestion, Seattle

Big Bad Data: The Uninformative Inrix Scorecard

Big data should be used for problem solving, not propaganda and promotion.

#NoNewRoads, Member Post, TransportationJoe CortrightFebruary 13, 2018traffic projections, data, traffic engineering

Predictive Planning

A mechanistic approach to city problems exposes us to two harms: one is that we employ the wrong solutions. The other is that we actually make things worse.

Gardner, Planning Profession, Top Story, Urban DesignSpencer GardnerSeptember 18, 2017traffic projections

Why urban freeway expansion is futile

The models used by highway engineers to analyze traffic congestion are woefully inaccurate and result in the creation of lanes and roads we don't need.

Top Story, #NoNewRoads, #DotheMathNorm MarshallAugust 10, 2017highway spending, congestion, traffic projections, traffic engineering

The Economics of the I-49 Connector, Part 2

The probability of the I-49 Inner City Connector creating 30,600 new jobs that would not have simply occurred somewhere else or are just being shifted from one now blighted place to the study area is precisely zero.