Does Destroying Highways Solve Urban Traffic Congestion?

Aerial view of collapsed sections of the Cypress viaduct of Interstate Highway 880 in Oakland, California in 1989. (H.G. Wilshire, U.S. Geological Survey)

Strange how the traditional laws of supply and demand go out the window when it comes to traffic. Studies over the last decade (like this one, this one, and this one; plus the book Suburban Nation) have pretty much dismantled the theory that more roads equal less traffic congestion. It turns out that the opposite is often true: building more and wider highways can increase traffic congestion. If only people like Robert Moses and Le Corbusier had known this before their grand urban plans left our cities clogged with traffic, and carved up by ugly, value-destroying highways.

As part of its series on urban transportation, the Mother Nature Network has this recent post, which includes a nice rundown of the evidence against highways as congestion relievers, plus a discussion of the latest idea taking hold in urban traffic management circles: destroy highways to reduce congestion.

A particularly dramatic case in point comes to us from traffic-clogged Seoul, Korea, where a few years ago a handful of “crazy” visionaries in the transport department somehow managed to sell a new mayor on the demolition of an elevated downtown highway. Fast-forward to today: the highway’s gone, a formerly paved-over river has been rehabilitated, the resulting green space is a source of urban pride, and — wait for it — motor vehicle travel times have actually improved in the neighborhood of the old highway.

The MNN piece reminds us that highway tear-downs have had similar results in New York City and San Francisco, but that it took natural disasters for those to happen: New York’s West Side Highway collapsed under the weight of a cement truck in 1973, and San Francisco’s Embarcadero Freeway was removed after suffering damage from the Loma Prieta earthquake in 1989.

One final tidbit on the economic costs of traffic: according to the Texas Transportation Institute, traffic congestion costs us $87 billion a year in wasted fuel. And that’s not even counting all those hours lost (and road rage)!


Andrew

Think you meant MNN, not MMN there.

But an interesting piece!

MRB

I'm a complete believer in "induced demand" - that is, more freeway capacity actually generates MORE congestion; by encouraging more people to use the highway now that it's "not as congested". Additionally, new highways also prime the pump for suburban home building, which creates new strain on the highway system.

That being said, "in the neighborhood around the old highway" isn't the place to look for increased congestion.

David

Summary of article:
"If no one can get to a neighborhood there won't be any traffic congestion in that neighborhood"

Dave

So, neither your summary nor the article really provide an explanation for why there is no reduction in traffic if you remove capacity. It would be interesting to see what the economic costs in terms of a lack of employment, delivery, etc are when road capacity is reduced. If traffic "just finds a way" as the linked article suggests, then we should be seeing increased congestion in other areas.

assumo

That is true - the test cases were mega-cities that had existing transit and road infrastructure to absorb demand. The highways that were demolished were also intra-city highways, which would not be expected to supprot interregional traffic.

Clancy

Nobody drives there anymore, there's too much traffic.

AaronS

I call "bull malarkey," at least in part.... You'll note that the excerpt read, "...motor vehicle travel times have actually improved in the neighborhood of the old highway." Well, OF COURSE they have improved in the neighborhood of the old highway--THERE'S NO MORE HIGHWAY!

Over time, if there is road capacity, market forces will likely work to cause people to keep buying cars, moving to the area, the local gov't to continue to allow more people to live there, etc. BUT when you take away the roads, several things ripple throughout the system. The "market forces" get to work on making people prefer public transportation, living elsewhere, making the elected officials try to curry favor by not allowing businesses or what-have-you that increases the ire of their constituents.

From my own (I think, thoughtful) observations of roads and traffic, it is seldom a case of not enough road(s), but of poor planning/design...and poor driving. For instance, you would think that an eight-lane interstate highway would never get clogged. But when a slow driver gets in the wrong lane, or someone doesn't think ahead, then has to stop traffic so they can get into the right exit lane, or exits back up because the red light at the bottom is poorly timed, etc., you start thinking, "Hey, we need another road."

I could HAPPILY drive across country on a two-lane road...if everyone did the speed limit...if speed limits made sense (none of this from 60mph to 35mph in the middle of nowhere just to give out speeding tickets)...if the red lights in small towns allowed you to get on through the town without long delays, etc. In fact, I purposely use such roads many times to avoid the interstate--better to enjoy scenery and calm than then dodging, ducking, high-speeds of the interstate sometimes.

Too much road causes gov'ts use it to sell their towns/cities to business ("Relocate here--we have great roads with lots of capacity to support your business), which brings in more people, which does X...Y...Z...until people hate the place.

With good design and absolute zero tolerance of poor drivers, rubbernecking, etc., a city could probably get by on far fewer roads than they have (after making the necessary design changes). But, indeed, at some point, even if you DID have perfect design, it cannot handle infinite growth. That's when you DON'T BUILD ANY MORE ROADS!!!--which eventually causes equilibrium...usually at the hands of mass transit, I imagine.

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jd

A splendid example of what passes for thinking among so called urban planners. If you tear it down, they will not come.

Joel Upchurch

My take is that the proponent of the scheme is saying everything is great but doesn't supply any statistics. Everything is peachy and we shouldn't get all analytical; this is, we should act like economists. I just want the the answer to one question, "where did the cars go?". Did people switch to public transportation? Did they move or change jobs so they didn't have they commute that way? Are they just taking a different route to work? Unless there is some evidence that commuting times actually decreased, then all I see is a park build at great expense on some really valuable real estate.

assumo

The theory takes an interperetivist approach at explaining phenomena that have occured on auxilliary highways in huge metropolitan areas. If you remove the road, the demand for travel still exists. In the case of a large metro area with many alternative routes, removal of one may not affect the system's ability to meet demand, but in a smaller area, removal of the highway could be crippling. Throughout CA's central valley, populous areas have popped up along the highway since the inception of the interstate system. These cities that were built around the highways lack the supporting street framework to give people the same amount of mobility in the absence of the highway. If no alternative were created, people would be forced to find work and schools much closer to home, but more realistically, they would languish in their inability to get anywhere on the clogged country roads. Large cities offer legitamate alternatives to the highway (if nothing else, the opportunity for lifestyle change), but take the cross-town route from Fresno or Bakersfield, and the cities would descend into chaos.

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tyler

I am a transportation planner in California, and I am a little miffed at Mr. Turner's article. First of all, he counters what he represents cartoonishly as a "one size fits all" solution with another, equally absurd proposition. If he were to look at travel demand models for every region that he proposes should be freed of its highways, he would find a great many where his theory does not hold. Highway deparments of 40 years ago severely misunderstood mobility, this is true, but "transportation planning" is a creation of the 90's, and the engineers and planners still have a wasy to go before they see eye to eye. That brings me to my second point: planners at State DOTs and regional transportation agencies are constantly pushing for innovative alternatives to the highway. The planning process is backlogged by about 15 years by design, which means we are only now seeing the fruits of planners' struggles since 1992. Look at the regional plans of the last decade and you'll see that things are in flux, but it will still be years and years until the construction culture catches up. Turner's postmodern "smash it to smithereens" take on the subject is cute, but devoid of any credit to the people who are actually trying to take what we already have and make it better and more efficient (a staple of sustainability, I might add).

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WalkableDFW

Lol. "traffic demand models." the ones that are rigged to conclude more supply is always necessary? Like or don't like this article because it supports or contradicts your assumptions, pick up Traffic by Tom Vanderbilt for a deeper view of the issues.

What happened in the cases cited above as well as in Seoul and Milwaukee which removed a freeway b/c they couldn't afford to maintain it (expect far more of that around the country), resulted in improved overall connectivity and spatial integration as freeways are about regional to regional connectivity, undermining local connectivity, the backbone of cities.

Furthermore, what occurs is a form of "import replacement." more things are done locally, now that a freeway is removed, a place becomes safer and more desirable, thus denser and more valuable.

Think about these examples as well. Pompidous widened the car travel lanes essentially from building face to building face. It pushed out all the pedestrians and all the businesses died. Since the mid 90s, Paris has systematically been replacing the travel/parking lanes of Champs Elysees along the side with increased pedestrian space. It's now some of the most valuable real
estate in the world.

When Copenhagen began removing cars and parking spaces all of the businesses objected. They're doing better than ever today because people want to be there.

And lastly, it is important clarify the difference between intracity and intercity freeways. The intercity are important in linking regional economies. The intra are destructive and disrupt local economies. This is why Eisenhower was appalled when cities and states bastardized his interstate system and ran amok with them.

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tylerh

"motor vehicle travel times have actually improved in the neighborhood of the old highway"

Isn't the point of a freeway to improve travels time to points that AREN'T in the neighborhood? Erecting a wall around each neighborhood would presumably also improve local travel times, but would greatly increase travel time to non-adjacent neighborhoods.

If eliminating freeways is such a great idea for large cities, then why don't more rational commuters avoid the current freeways and use existing "surface" streets?

James

Because many (most?) commuters - no, make that most drivers - aren't rational?

If asked, I can provide plenty of observational evidence to support this thesis :-)

bob

If there were no roads, there would be no congestion on a road.

It's simple supply and demand. You decrease the capacity of your road network (supply), and the cost of driving goes up (price), and demand goes down.

The question is whether the region is better off in some obscure measure, like happiness.

Eric M. Jones

That's a hell of a coincidence! On December 15, 1973, the northbound lanes between Little West 12th Street and Gansevoort Street collapsed under the weight of a dump truck, which was carrying over 30 tons (27,000 kg) of asphalt for ongoing repairs of the highway, too!

Ryan

Traffic is caused by intersections, on and off ramps, and the forced changes in speed of vehicles. That's just simple math.

Shane

Fascinating! I'd like to see how public transport and other projects impact congestion too.

Alex

Like many of the commenters I agree that the article ignores the 'unseen'. Reducing capacity may reduce congestion, by people travelling less. But on the margin it may mean someone giving up work. Or instead of commuting into a city they may travel outwards out (maybe a longer journey but quicker). Or they may rent a city centre flat during the week, pushing up rental prices. Or the congestion may simply move elsewhere.
Surely the best approach is to estimate the external costs of motoring (CO2, congestion, pollution, accidents, lack of exercise, noise..... ) and tax accordingly. This may give you car taxes like here in the UK (if my sums are right I'm paying the equivalent of $7 per US gallon for fuel). Charge those costs, see how much traffic you get, plan accordingly. Job done. But of course it would be political suicide to even suggest it.

James

"...if my sums are right I’m paying the equivalent of $7 per US gallon for fuel..."

But you are probably paying as much per mile as the typical American SUV owner does when gas is $3.50/gal.