Accounting for the “iron law of congestion”

Why is building more lanes to address traffic issues not the best way to go? See the iron law of congestion:

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There’s a name for the principle behind that apparent paradox: induced demand. Economist Anthony Downs is often credited with first articulating this “iron law of congestion” in 1962, as construction crews were hacking interstates through American cities. Downs published a seminal paper with a stark warning: “On urban commuter expressways, peak-hour traffic congestion rises to meet maximum capacity.” In other words, adding lanes won’t cure snarled traffic; the additional car space inevitably invites more trips, until gridlock is as bad as ever.

Downs was not the first to sound an alarm about the futility of expanding urban roadways — not by a long shot. In 1932, an association representing streetcars warned that “as fast as improvements are made in existing arteries of travel … they are saturated by an increasing volume of traffic.” In 1955, urban observer Lewis Mumford wrote a series of essays in the New Yorker titled “The Roaring Traffic’s Boom,” in which he memorably compared a highway planner widening a congested highway to “the tailor’s remedy for obesity — letting out the seams of trousers and loosening the belt. [T]his does nothing to curb the greedy appetites that have caused the fat to accumulate.”

Downs’ iron law applies not only to U.S. cities, which have grown more traffic-jammed despite billions of dollars in fresh pavement, but also to those around the world. Highway expansions in Norway and Britain haven’t reduced congestion there, either. The principle now meets little opposition among economists and urban planners. “It’s widely accepted,” says John Caskey, who teaches induced demand as part of his urban economics course at Swarthmore College. “For economists interested in urban transportation, there isn’t really any debate.”…

But turning down a new highway lane remains politically challenging. “The highway construction system has vast momentum,” says Rose, the historian. “It has the authority of highway contractors, builders and labor unions. Here is something that labor and management really can agree on: a highway contract.” The auto industry, too, continues to benefit from ongoing investments that expand the “floor space” allotted to its products. In 2019, Tesla CEO Elon Musk tweeted that induced demand “is one of the most irrational theories I’ve ever heard.”

Build it and they will come.

As I read through the longer narrative in this article, it seems that the needs of the automobile were prioritized by drivers, businesses, those in the road industry, and politicians. This has been going on for roughly a century; would academic theories with evidence behind them be able to overcome these interests?

Perhaps at some point in the future, we will able to look back at “peak road” or “peak highway.” Is there a point where new roads and highways or lanes are no longer pursued in the United States? Even if population growth stagnated or slowed, would the United States continue to build roadways? Maybe the costs of maintaining all those roadways will help lead to this moment. It is hard to imagine other scenarios; even as fewer people drive to work compared to earlier years, traffic continues.

“Driving in ‘American Dream mode'”

Driving during a stretch of pleasant fall weather, I thought of a phrase I heard a few months back in a radio conversation: “driving in ‘American Dream mode’.” The idea was this: putting the windows down, turning up the radio or music, and enjoying the drive is an ideal expression of the American Dream. Freedom. Cars. Moving quickly through the landscape.

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Many car commercials play off this idea. These commercials rarely feature traffic and stopping for traffic lights or stop signs. The driving is often through pleasant landscapes. The drivers and the passengers are enjoying the experience. The cars are new and loaded with features.

Numerous social forces converged to this point where a particular driving experience embodies the American Dream. The construction of roads and highways. Sprawling suburbs. The rise of fast food, big box stores, and road trips. Driving is an essential part of the American way of life.

Even if relatively few people get to regularly drive in “American Dream mode,” it is a powerful symbol.

The limited safety of pedestrians and bicyclists even in quiet residential neighborhoods

Street and intersections in quiet suburban subdivisions are not necessarily designed with the safety of pedestrians and bicyclists in mind:

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The station reached out to county officials and the local police precinct; everyone sure scratched their heads about that one. There was supposed to be a stop sign there, said the county, and they didn’t know why there wasn’t one installed. The police made sure to point out that it wasn’t their fault, either, because, they said, residents hadn’t complained. “Some residents have now reached out to us requesting additional signage,” said the precinct’s commissioner, James Mett. “In the coming days, we plan to examine and research the issue to determine the best course of action moving forward.” A few phone calls later, it was announced that a new stop sign would be installed Thursday.

So, that’s one thing that made this street unsafe. But there are plenty of other problems, not unique to this intersection but common to many, many American streets, that also made it unsafe. There’s no signage of any kind to alert drivers to the possibility that walkers or cyclists might want to cross. There are no traffic-calming design elements, like speed bumps, raised crosswalks (or any kind of crosswalk), or extended curbs. There’s no protected bike lane.

The speed limit on this road is 30 miles per hour, as it is on roads in all Texas cities. Last year a Texas lawmaker introduced a bill to lower the speed limit on such roads to 25 miles per hour. Cars traveling 30 miles per hour are 43 percent more likely to kill pedestrians they hit than cars traveling 25 miles per hour, according to the AAA Foundation for Traffic Safety. This is the lawmaker’s third attempt to pass this bill, and it seems to have been just as successful as the first two times, as nothing has happened to the bill in more than a year. (We don’t know how fast the driver of the Hyundai was traveling. Maybe she was going less than 30 miles per hour. Or maybe she was going faster; after all, Google Street View suggests you can drive the entire length of Kings Mill Road, a circuit of nearly a mile, and never see a single speed limit sign.)

And notably, the driver who struck and killed Chase Delarios was driving a midsize SUV. The heavier the car, the more likely it is to kill a person if it strikes them. At between 3,500 and 5,000 pounds (depending on specific model), a 2017 Hyundai Santa Fe is more than a match for an 8-year-old and his bike. (The post-crash local news coverage shows the bike, horribly, jammed under the Hyundai’s rear wheel.)

And the conclusion:

Like most American streets, Kings Mill Road is not a safe area for pedestrians or people riding bikes. It’s designed for drivers, and drivers use it that way. That’s the system we’re trapped in…

In the United States, cars and vehicles with engines rule the roads. We have built whole systems and ways of life to accommodate them and ease their travel. It is supported by public and private money, public sentiment, and an ongoing series of decisions.

If you are traveling via other means, you have to be aware and careful. Know where vehicles are at all times. Be cautious in crossing, even at clearly marked walkways. Be ready to move quickly if needed. Make yourself visible to vehicles.

To change this or seriously address this would require a long-term effort to redesign basic aspects of everyday American life. It can be done, but a sustained series of actions is difficult to organize and execute.

Suburban voters and the French presidential election

Residents of the American suburbs may hold the keys to major political outcomes. Is the same true in France?

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ON THE FRINGES of greater Paris, where urban concrete meets farmed fields, lies the suburb of Saint-Brice-sous-Forêt. Gently curved streets of two-storey houses, each with a parking space and garage, cover what were once apple and pear orchards. The narrow high street has just one café, and a “Cheesy Pizza” takeaway joint; but there is a drive-in Burger King on the outskirts. This is what the mayor, Nicolas Leleux, calls “the border of two universes”: city and countryside. It captures the worries and hopes of middle France, and exemplifies a crucial electoral battleground for April’s presidential poll.

Shy of extremes, the suburb tilts to the centre-right. In 2017 Saint-Brice-sous-Forêt preferred the centre-right presidential candidate, François Fillon, in the first round, but backed the centrist Emmanuel Macron against the nationalist Marine Le Pen in the second. In 2020 it replaced a centre-right mayor with Mr Leleux, a former navy submariner who belongs to Mr Macron’s party. Locals, in other words, may be torn at the presidential poll this time between a vote for Mr Macron, assuming he runs for re-election, and his centre-right rival, Valérie Pécresse. A well-known figure locally, she is the president of the Ile-de-France region, which encompasses the city of Paris itself and Saint-Brice-sous-Forêt, 17 kilometres (11 miles) away…

What comes into sharpest relief in Saint-Brice is the collision between the needs of daily life, notably the car, and the desire for a greener future. A place of quiet middle-of-the-road aspiration, it evokes what Mr Leleux calls the “French dream”. “People have left the city to come here, not to live in a tower block, but in a house with a little garden, with neighbours, and a place to barbecue.” Nearly 88% of households own at least one car. His task, he explains, is to reconcile that dream with the need to reduce car usage. Few can afford an electric vehicle. Mr Leleux is planning cycle lanes and building a bike shelter at the railway station, on a direct line to Paris. Yet on a cold day in January there are no cycles to be seen on the streets…

Fashionable Parisian talk of the ideal “15-minute city” is all very well, says Mr Leleux. The reality is that to buy a baguette in under 15 minutes without a car is not possible in much of suburbia. If anybody has learned this, it ought to be Mr Macron, who won a huge majority of the vote in big cities in 2017, but later faced months of gilets jaunes protests. For now, insists the mayor, locals credit the president nonetheless with having been a “good captain” in difficult times. In April, it is on the streets of middle France, not the parquet-floored salons of Paris or its tenements, that such a claim will be tested.

The focus in this analysis is on cars as a divisive political issue. Can suburbanites afford electric cars? If they cannot, what does this mean for suburban life? I could imagine a similar question in the United States with numerous manufacturers moving to electric vehicles

But, I wonder if the electric car is just a symptom of deeper differences based on how the car factors into the fabric of suburban life. In the United States, I have argued that homes, cars, and a way of life are all connected in suburbia. It is not just that a new kind of car is expensive; any disruption to driving changes suburban life. Cars help enable larger yards, private space, and separated land uses. People want amenities to be within a 15 minute drive and this significantly widens their travel radius compared to walking.

Perhaps the other possible suburban disruption on this scale would be to threaten single-family homes and yards. I put the single-family home as the #1 feature of suburbs that Americans love. (Cars and driving is at #5.) Yet, it is hard to imagine suburbs today without homes and cars together.

In the meantime, I will keep an eye out for more analysis from France to see if the suburbs matter in elections in the same way as they have mattered in recent American election cycles.

An argument for why “cars are simply vastly superior to transit alternatives”

An economist makes the case for why Americans choose cars:

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Automobiles have far greater and more flexible passenger- and cargo-carrying capacities than transit. They allow direct, point-to-point service, unlike transit. They allow self-scheduling rather than requiring advance planning. They save time, especially time spent waiting, which transit riders find the most onerous. They have far better multi-stop trip capability (which is why restrictions on auto use punish working mothers most). They offer a safer, more comfortable, more controllable environment, from the seats to the temperature to the music to the company.

Autos’ superiority doesn’t stop there, either. They expand workers’ access to jobs and educational opportunities, increase productivity and incomes, improve purchasing choices, lower consumer prices and widen social options. Trying to inconvenience people out of their cars undermines those major benefits, as well.

Cars allow decreased commuting times if not hamstrung, providing workers access to far more potential jobs and training possibilities. That improves worker-employer matches, with expanded productivity raising workers’ incomes as well as benefiting employers. One study found that 10 percent faster travel raised worker productivity by 3 percent, and increasing from 3 mph walking speed to 30 mph driving is a 900 percent increase. The magnitude of such advantages is seen in a Harvard analysis that concluded that for someone lacking a high-school diploma, owning a car increased their monthly earnings by $1,100.

Cars are also the only practical way to assemble enough widely dispersed potential customers to sustain large stores with affordable, diverse offerings. “Automobility” also sharply expands access to social opportunities. 

My sense is that Americans tend to agree with this, even if they do not think much about other transportation options.

At the same time, I could imagine two questions about this superiority:

  1. Is part of the superiority of the car due to the ways that American life are structured around cars? It is not just that people choose cars: the American way of life encourages car use.
  2. Are the individual choices made for cars best in the long run for communities and societies? Many individuals may like what cars enable but others would argue it leads to bad outcomes for the whole (one example here).

This belief in the superiority of cars also makes it difficult to find monies and the will to pursue other transportation options.

In a society devoted to driving and business, what alternatives are there to rental cars?

The rental car industry has had a difficult year, customers are unhappy, and some companies are still making money. In a country that likes driving, has planned around driving, and has oodles of cars plus encourages business activity, what could be done to not depend on rental cars? A few options:

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  1. Car sharing services. There are more of these around today. Cut out the middle-man business and just deal with a private car owner for your transportation.
  2. Taxis and/or ride share companies. These are more available in some places than others and do not allow the same freedom as being able to drive a rental car wherever and whenever you would like.
  3. Public transportation. Even less available outside of denser urban areas. And even in places where mass transit is plentiful, many people still opt for private vehicles.
  4. Walking or bicycling. Very difficult and possibly dangerous in many locations.
  5. Borrowing a car from family or friends or doing without it for a time. It could be done but the location and time frame is very important.

Thinking back, I can recall multiple trips where a rental car was a necessity in order to get where we wanted to go. At the same time, some work trips did not require a vehicle because the location of the meeting was in a large city with public transit options. And if you are in a suburban or more rural setting and your car is in the shop for more than a day, a car rental may be very necessary.

Does this mean Americans must put up with rental cars forever? Perhaps someday there will be fleets of electric vehicles for all to access. Until then, renting a car may be a necessary evil.

The foresight of old railway viaducts

In regions like Chicagoland where there are numerous railroad lines and at-grade railroad crossings, old viaducts exhibit a measure of foresight that benefits today’s residents:

Google Street View image of Vollmer Road viaduct

That factory still operates as Chicago Heights Steel, and the cobblestone portion of Main Street is mostly a driveway leading to it. But just past the factory is a secret passageway of sorts, an ancient viaduct just wide enough to allow one vehicle to pass under the old Elgin, Joliet & Eastern railroad tracks…

There are areas, though, where there are no ways around it, and if you get stopped, you just have to abide. I’ve lived in those areas, but I don’t anymore. The main train line by me is above grade and it’s great. The old Illinois Central tracks, which include what’s now known as the Metra Electric District commuter line, traverse the area atop a big berm as unobstructed motorists cruise underneath through a series of viaducts from Sauk Trail all the way into the heart of Chicago.

According to Metra, the grade separation was a direct result of Chicago hosting the 1893 World’s Columbian Exhibition — city leaders didn’t want messy train deaths to tarnish the event’s image. In the years after those initial express trains from downtown to Jackson Park for the World’s Fair, commuter trains made their way to the suburbs, with Flossmoor getting service in 1900 and Matteson by 1912. The raised platforms, tracks and viaducts followed with the entire line being above grade by the 1920s…

Viaducts are harder to come by these days than they were in the golden age of railroads, and I only know of a few that have been constructed in my lifetime. Despite the hassles that can come along with them, motorists, and likely train engineers too, are happy we have the ones that are here.

Even as railroad lines help put many suburban communities on the map and still provide access to big cities, many local residents just see them as a hassle for the traffic and noise they create. With the automobile dominating suburban travel, trains are nuisance when they block vehicle flow.

I am familiar with numerous railroad viaducts in suburban communities in addition to the ones mentioned above in the south suburbs of Chicago. They were ahead of their time as they allowed access under the railroad tracks, sometimes even before cars were around. Local leaders and officials they foresaw the problems that might arise between ground-level traffic and trains and therefore separated the two flows to let each move on their own. This helps avoid safety issues that still plague communities today.

At the same time, not all of these viaducts have been treated well. As the article notes elsewhere, they can have drainage issues. Their original size is often an issue as today’s vehicles and/or traffic flow is larger, meaning that old viaducts need to be expanded. Letting one car through at a time is better than nothing but many communities would benefit from two lanes each way being able to go under the tracks. Foresight in infrastructure is helpful but it needs consistent attention to keep up with repairs and expanded suburban populations.

Misplaced nostalgia in Cars for the pre-Interstate days

On a recent rewatching of the Pixar film Cars, I was reminded of something that bothered me at my first viewing soon after the movie came out in theaters. Here is the issue: one of the key points of the plot is that the small town of Radiator Springs suffered when Interstate 40 opened nearby. But, the film makes clear that the issue is the interstate, not driving in general.

This movie celebrates driving. The main character, Lighting McQueen, is an ascendent race car and he needs to rediscover his love of the road. He does this after getting stuck in Radiator Springs. The combination of relationships, the lanscape, and a reorganizing of priorities helps him see that driving should be fun and relaxed, not just about winning and being brash.

The Interstate represents all that is bad. McQueen gets into trouble when he is accidentally dumped off on the side of the Interstate and gets lost. Radiator Springs is just a shell of itself because all the traffic that used to come through town now just whizzes by on the Interstate. Route 66, the road of quirky local establishments, small towns, and vistas, gives way to the straight and multi-lane highway where people just want to go as fast as they can to get to the real destinations.

The movie says everything went wrong with the Interstate. Its emphasis on efficiency came at the cost of communities. It left places behind; not just urban neighborhoods where new highways bulldozed homes and establishments but also small towns in the middle of the desert. McQueen would have left it behind too if he wasn’t forced to stay.

Is the real problem the Interstate or an American way of life built around driving? Sure, the Interstate promotes faster driving but cars themselves promote a different kind of life, one lived at faster speeds. Small towns can force people to look a little more closely with reduced speed limits and speed traps. But, they cannot force them to stop or to care or not just stop at a fast food joint and filling station and get back to the road quickly.

Once Americans had cars in large numbers, they wanted to go places. The open road offered opportunities. Some will want to drive and take their time. Some will want to get places as quickly as possible. Others just need to get from Point A and Point B to do what they need to do on a daily basis. Some of the car commercials I see today make me laugh as they try to say that a sportier exterior or 50 more horsepower transform the daily commute; how many people today really love driving?

Or, how many Americans really like small towns? They may hold it out as an ideal but the population shifts in the last century – both shaped and echoed by the Interstates – have been to metropolitan areas, particularly suburbs. Radiator Springs might be nostalgic and an interesting place to visit. But, it is not the place many would choose as they prefer other amenities including the jobs present across metropolitan regions.

All together, Radiator Springs and its ilk would not likely spring back to life just because the Interstate disappears. Indeed, it is revived in part by the end of the movie because people can get to it via the Interstate and they are drawn initially by the celebrity of Lightning McQueen. Now, Radiator Springs can be a tourist destination and some residents may even rue the day when new residents want to move in and new development threatens what the community once was. Here, cars are both the problem and the answer and without a broader discussion about cars and driving, Americans may just be stuck between wanting places like Radiator Springs to survive and the need to drive quickly to the next opportunity in life.

More obnoxious in the suburbs: Prius with Coexist sticker, oversized pickup with Blue Lives Matter flag in the bed, or car with super-loud muffler?

Cars are not just cars; they are an embodiment of who Americans are. Even as suburbanites like cars, here is a quick description of three noteworthy vehicles that might raise some suburban hackles:

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-The Prius driver with the Coexist sticker on the back. Not only are they already signalling their green bona fides with their car choice, they accentuate their tolerance for different religious groups. Prius drivers are not thought of as being aggressive but the bumper sticker suggests they are interested in trumpeting tolerance or pluralism.

-The large pickup truck with the American flag and Blue Lives Matter flag proudly waving from the truck bed. These are not usually small trucks; they tend to be big versions that tower over other vehicles and can afford the loss of fuel efficiency to show their pride in country and police.

-The vehicle that makes itself heard through an intentionally loud muffler. This is not the occasional car that needs a muffler repair; this is a vehicle that added the sound so that it could be heard a mile away on a quiet night. Seeing the green light at a traffic light is an aural experience with these vehicles.

Other options for vehicles that might irritate suburbanites:

-The cool Tesla drivers. They can’t show off their autopilot features in stop and go suburban traffic but the quiet, sleek vehicles make their own statement.

-The upgraded SUV drivers. They do not just have a CRV or Rav4; they have the latest Lexus version or the Porsche Cayenne or a luxury Escalade.

-The person who lives on a nice street who drives the rusting clunker. I know many of your below-the-radar American millionaires drive their Toyota Camrys or Honda Odysseys into the ground but there are expectations about what a vehicle should look like paired with particular residences.

-Anyone who drives strictly slightly below the speed limit. This has less to do with the vehicle and more with the driver but the cool factor of the car isn’t going to save someone from the ire of drivers.

Do Americans actually like to drive or do they say this because much of American life requires driving?

Do Americans actually like driving? Or, do they just do it a lot?

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Many Americans must drive on a regular basis. They need vehicles in order to get to work, obtain groceries and other goods, take advantage of recreation opportunities, and get to school. Many communities are designed around roads and emphasize moving large numbers of cars through areas at fast speeds. Americans have a system that privileges driving.

Americans might cite numerous aspects of driving and cars that they like. Driving is its own unique challenge requiring skill and attention. The driver is responsible for maneuvering a several ton vehicle. There are rules to be followed and ways to make driving more interesting. The average person does not have many other means to match the feeling of speed that a car can offer. Vehicles themselves can spark interest, ranging from their styling to their upkeep to their different features.

Additionally, driving has cultural meanings attached to it. From the beginning of cars, Americans loved the mobility and freedom they offered. Cars are more individualistic than mass transit. Vehicles represent progress with people behind the wheel. Cars and driving skills say something about their owners.

With an infrastructure that emphasizes driving and features of driving that Americans like, perhaps these two are simply intertwined today. Cars and driving are just part of the American way of life. Perhaps American drivers do not need to even like driving; they just have to tacitly support the structure that keeps driving as the primary mode of transport. Liking driving could then a resignation to the status quo or finding joy in what they are going to do anyway. Or, it could genuine joy at sitting behind the wheel. Changing this love of even or even acceptance of driving would take significant time and/or effort given how Americans feel about driving.