Photo : AP

Five years ago, the California Department of Transportation completed a $1.6 billion project to rebuild a 10-mile portion of the Sepulveda Pass of the 405 in Los Angeles. The project, like nearly all highway expansion projects, was billed as a way to relieve congestion and improve travel times. Often, such projects are also sold to the public as environmentally friendly because stop-and-go jams result in higher emissions than free-flowing traffic.


But the Sepulveda Pass project accomplished none of those things. An analysis by the University of Southern California-affiliated non-profit organization Crosstown found that during the project, traffic speeds were much higher than right afterwards because so many drivers heeded the “carmageddon” warnings and found alternate routes.

But once the project wrapped up, speeds tanked right back to where they were before. And in the five years since the project was completed, traffic is even slower.




This was an all too predictable outcome. The concept of induced demand—that building more lanes and more roads results in more cars and more traffic—has been around almost as long as cars itself.

For generations, transportation planners have steadfastly ignored these lessons and continued to build more roads, bridges, tunnels, and highway lanes, tossing billions upon billions of dollars down the proverbial drain. But now, we have a very good reason to finally, finally stop this madness. More roads means more vehicle miles traveled, and more vehicle miles traveled means more emissions. To have any fighting chance of reducing emissions in time to stave off the worst effects of climate change—something millions of people around the world are demanding the adults in the room do today—the least we can do, other than absolutely nothing, is to stop thinking “more roads and highways” is the immediate go-to solutions to our transit woes.

In fact, there’s real evidence that building more highways, specifically, is making things considerably worse.

I know proposals on reducing emissions to meet climate goals often sound daunting or require some degree of personal sacrifice. But this is an easy one, if not the easiest one. In fact, we ought to have done it a long time ago.


In The Power Broker, the seminal biography of Robert Moses, the man who built so many highways, parkways, and bridges in the greater New York City area, biographer Robert Caro explained induced demand as well as anyone, tracing the concept all the way back to 1929:

Watching Moses open the Triborough Bridge to ease congestion on the Queensborough Bridge, open the Bronx-Whitestone Bridge to ease congestion on the Triborough Bridge and then watching traffic counts on all three bridges mount until all three were as congested as one had been before, planners could hardly avoid the conclusion that “traffic generation” was no longer a theory but a proven fact: the more highways were built to alleviate congestion, the more automobiles would pour into them and congest them and thus force the building of more highways – which would generate more traffic and become congested in their turn in an ever-widening spiral that contained the most awesome implications for the future of New York and of all urban areas.


Year after year, city after city, project after project, induced demand remains the rule of thumb.



It is not quite right to say we have learned nothing since. We have, in fact, learned a great deal, coming up with more creative and precise methods for measuring induced demand. The Crosstown analysis is one such example. Another is this study from California State, Northridge professor Kent Hymel who found that for every one percent of lane mileage added, there is a one percent increase in vehicle miles traveled. After a mere five years, any speed improvements are negated, spurring new calls for new lanes and new highways. It is the perpetual highway-building machine.




It is, however, all too correct to say we have done nothing differently. What ought to be yet another scandal of misused public funds—Lyle Lanley ought to have been proposing a two-lane highway widening instead of a monorail—is merely another reminder that America’s only transportation policy is to repeat the mistakes of the past as often as possible.



One needs to look no further than the same agency that conducted the Sepuvleda Pass project. One would think, after such a disaster, Caltrans would re-evaluate its highway-building projects.




No such luck. Caltrans is spending $1.9 billion to widen seven miles of I-5. According to Streetsblog, the agency will then move on to widening another section of the 5 afterwards for another $1.3 billion, all to “minimize congestion” and “reduce pollution.” That’s $3.2 billion—assuming no cost overruns, which all the projects mentioned so far have had in spades—on projects we know from 100 years of evidence will not make anything better. That $3.2 billion could get you a good chunk of a light rail line in Los Angeles, or a whole network of bus rapid transit lines, both of which actually would minimize congestion and reduce pollution.

The definition of insanity is not repeating the same thing over and over and expecting different results, but that is the slogan of American transportation policy.




Indeed, it is not just Los Angeles, and not just California. As urbanism writer and Gizmodo alum Alissa Walker detailed in Curbed, Maryland’s Department of Transportation is widening highways while killing public transportation projects.

I’m picking on Maryland here because their DOT fired off the most ridiculous tweet claiming that “Traffic relief can help address #climatechange,” which is the 21st Century version of claiming smoking menthols can help address lung cancer.






But it is not just Maryland. Every single state spends gobs of money on more or wider roads even as repair backlogs of their existing roads mount. According to the non-profit Transportation for America, the nation’s public road network grew by 223,000 miles from 2009 to 2017, an unacceptable public policy both from a climate policy standpoint and a fiscal responsibility one.


On the climate side, the stakes of repeating these mistakes over and over and over again are even higher than before; even more significant than, as Caro put it, insuring that getting from one place to another “would be an irritating, life-consuming concern for its... residents.” And transportation projects that result in more emissions is one thing we absolutely cannot afford to be doing.



A moratorium on new lane miles would accomplish multiple climate goals at once. It would, of course, put a halt to the most obvious elements of induced demand. It would also halt sprawl, encouraging denser living which might—just might!—encourage folks to walk or bike in their cities, to say nothing of public transportation.


And such public transportation—or perhaps even just maintaining the roads we already have—could be funded in part with all the money saved not only by forgoing the very expensive road-building projects, but also by forgoing future bills to maintain that road. Transportation for America estimates it will cost $5 billion just to maintain the new roads built from 2009 to 2017 even as the existing road network remains in desperate need of more repairs.



Proposals to have a moratorium on highway-building used to be confined to urbanist and climate change activist circles, but it is now mainstream enough that the Brookings Institution has dipped its toes in the water. It’s proposing we measure the effectiveness of highways completely differently. That is, in a way that would make it difficult to justify building more of them.




But, it is not so mainstream that any Democratic presidential candidate is proposing anything like it in their climate plans. As Walker pointed out at Curbed, nearly every candidate has something to say and billions of dollars to give (or in Bernie Sanders’s case, trillions) to subsidize electric car purchases and charging infrastructure. But none have called for a moratorium on highway construction, a lever the federal government could very easily pull considering the vast majority of highway construction funds come from the Feds.



And even Bernie’s $3.5 trillion (with a “T”) earmarked for EV adoption is still missing the bigger picture. Indeed, electric cars are a cleaner form of transportation than gas-guzzling ones, reducing the life cycle emissions per car by about half, depending on how much electricity you get from renewable energy.


But we won’t be able to replace gas cars with electric ones—or sufficiently clean up the electric grid—fast enough. Even if every single car sold from this moment on is 100 percent battery-powered, nearly all of the cars and trucks on the road today are going to take at least a decade to reach the end of their useful lives.

Electric car sales are rising rapidly, but still make up only about 1 or 2 percent of overall vehicle sales. Even assuming the super aggressive EV subsidies many Democratic presidential candidates have proposed, it will still take decades for EVs to become just a majority of cars on the road.




And yes, we know it sounds weird to say “drive less” here at a car enthusiast website; but we’ve always maintained there’s a difference between car culture and commuter culture. The latter is literally far more toxic. And for decades, American public policy has treated driving as not an enthusiast activity but rather as the one, default way to get around. Not only has this made our cities worse places to live, it’s also an untenable state of affairs for our climate.


The path forward is clear. And a necessary first step, but only a first step, is to stop building more highways. It’s either that, or wait for them to be underwater.

