Engineering Insanity on Display: The Diverging Diamond Interchange

Charles Marohn is the critic the transportation engineering field desperately needs.

Over and over again, this former traffic engineer and head of the engineering reform nonprofit Strong Towns has made himself the voice of reason to a field gone mad on automobiles.

His latest coup is a sardonic verbal takedown of a nightmare “complete street” interchange that Missouri engineers are calling “progress.” But the design is less than revolutionary, preserving the field’s allegiance to almighty car capacity. The project’s real triumph is in finding ways to satisfy the most basic elements of complete streets while completely missing the spirit of the movement.

Says Marohn of the video:

Did we need more proof that the engineering profession is insane than this video of the “diverging diamond”? If we had infinite resources (we don’t), this would still be crazy, but the fact that we’re broke just shows you how insulated from reality so many of them are.

Sometimes I feel as if I’m shouting into the wind with the engineering profession. This may just be more of that. If nothing else it was therapeutic to me.

  • vince

    I agree with the creator in lamenting highway-oriented development, but as long as state DOTs are building interchanges this seems like an improvement on older designs.  Especially if the safety claims are correct.  The center walking/biking median in the video was stark and un-friendly, but there is a potential to add trees, etc. to create a much nicer experience.

  • Why don’t we just build a pedestrian bridge? In the city I live in, we have a proposal to lower the speed limit to just 30 kmh to protect pedestrians, but our lord mayor admits that many pedestrians ignore the lights, also note that we have no grade separated pedestrian network, like one finds in cities like Toronto, Calgary and in Dallas, not even in our own CBD.


When the Streets Belonged to All, and All Belonged on the Streets

It’s been a little over a year since Raquel Nelson was convicted of vehicular homicide for attempting to cross a street with her kids in suburban Atlanta. Much of the public responded not with outrage, or demands that municipalities improve conditions for pedestrians, but with victim-blaming vitriol, passed along in news stories with headlines like […]

How Engineers Deflect Criticism of Their Dangerous Designs

As people who’ve tried to make their neighborhood streets safer for walking and biking can tell you, engineers are amazingly adept at shutting down dissent. Chuck Marohn at Strong Towns — an engineer himself — knows the drill inside out (it inspired this classic animation from 2010). In a new post, he explains: Transportation engineers can be intimidating. They are […]

Man Who Painted Speed Warning on Street Vows to Fight Charges

A Pennsylvania man faces charges of criminal mischief and disorderly conduct for painting a warning to speeding drivers on his street. John Cherok appealed to the city about drivers going dangerously fast in front of his bookstore in McDonald, Pennsylvania. The city, for its part, conducted a study and told him speeding wasn’t a problem. The […]