RealClearScience Newton Blog

How to Make Sure a Pandemic Like Covid-19 Never Happens Again

Ross Pomeroy - April 4, 2020

The SARS-CoV-2 coronavirus pandemic may still be in its early stages, and though it's difficult to see past shelter-in-place orders, infection reports, images of crowded hospitals, and record unemployment, you can rest assured in knowing that this public health crisis will eventually come to an end. It may take many months, but sports will resume, bars and restaurants will reopen; for the most part, life will return to normal.

But a comforting new normalcy must not be accompanied by complacency. There are lessons to be heeded, policy changes that must be implemented, and mistakes that cannot be repeated. Here are five ways the world can mitigate, or even prevent, a future pandemic.

1. Ban the sale of wild animals and freshly-slaughtered animals at wet markets in China and around the world. The likeliest source for the coronavirus is the Huanan Seafood Wholesale Market in Wuhan, China. A wet market also likely spawned the SARS outbreak in 2003. At this market and others like it, humans and wild animals gather in cacophonous, crowded spaces, exchanging goods, money, and germs. It was here where scientists hypothesize that the coronavirus jumped from a bat, then possibly to a pangolin, then on to humans. While wet markets offer a needed economic outlet for thousands of poor farmers, they are notoriously unsanitary and unregulated. At the Huanan Market, journalists documented animals being openly slaughtered and skinned while blood, urine, and feces drenched walkways. Sellers proffered a menagerie of animals including spotted dear, porcupines, otters, ostrich, crocodiles, and bats.

In this Feb. 5, 2020, photo, workers wearing protective gears prepare to spray disinfectant as a precaution against the coronavirus at Namdaemun Market in Seoul, South Korea.

In late February, the Chinese Communist Party banned wet markets, noting "it is necessary to strengthen market supervision, resolutely ban and severely crack down on illegal wildlife markets and trade, and control major public health risks from the source." Let us hope this strong statement will be backed up with meaningful action.

A Surprising Paradox of Major Floods

Ross Pomeroy - March 31, 2020

The spring flood season is upon us in the United States. As temperatures rise, the snows of winter melt and trickle across the landcape into rivers, whose steady flows turn to rushing torrents. Rising waters boosted by wet weather overflow their banks and pour onto farm fields, highways, and city streets.

Last year, record floods along the Missouri and Mississippi Rivers caused $2.9 Billion worth of damage in Nebraska and Iowa, flooding at least one million acres of farmland and killing three people.

While floods and other natural disasters can inflict unfortunate death and destruction upon individuals, they can paradoxically benefit communities in the long run.

In the short term – over a span of a few years – floods can transform urban areas into downtrodden, waterlogged ghost towns. But you might be surprised to learn that in the long term – think more than ten years – floods and other natural disasters actually seem to grow economies and populations. Laurence C. Smith, a Professor of Environmental Studies and Professor of Earth, Environmental and Planetary Sciences at Brown University, explained this apparent paradox in his forthcoming book Rivers of Power.

An Archaeological Explanation for the Story of Noah's Ark

Ross Pomeroy - March 26, 2020

The Biblical story of Noah's Ark is widely known: God decides to wipe the Earth clean of wickedness and tasks the righteous Noah and his family to safeguard themselves along with all the world's animals inside a gigantic wooden ark in order to ride out a global 150-day flood.

Though some take the story literally, there's no archaeological evidence that such an ark ever existed, nor is there any geologic evidence of a cataclysmic global flood. That doesn't mean the story wasn't based on historical events, however.

As Laurence C. Smith, a Professor of Environmental Studies and Professor of Earth, Environmental and Planetary Sciences at Brown University, recounted in his forthcoming book, Rivers of Power, a story nearly identical to Noah's is "written on one of the twelve tablets of the Epic of Gilgamesh," predating the Old Testament account by more than a thousand years.

"Numerous credible studies suggest that a real-world local catastrophe may have inspired the story," he writes.

Four Ancient Greek Inventions That Were Way Ahead of Their Time

Ross Pomeroy - March 19, 2020

Aristotle, Plato, Socrates... Ancient Greece's charismatic philosophers define the civilization's legacy in popular memory. Often forgotten are the technological inventions that set Greece apart from other societies during classical antiquity, which roughly spanned between the 8th century BC and the 6th century CE.

Mechanical engineer Kostas Kotsanas wants to change that. Perhaps the foremost expert on ancient Greek technology, Kotsanas created the Kotsanas Museum of Ancient Greek Technology to apprise the public of Ancient Greece's formidable technological prowess. The stars of the show? Nearly 300 models of ancient Greek inventions, all exhaustingly researched and painstakingly built by Kotsanas himself. Here are four of the most incredible:

Plato's Alarm Clock

This may be the first known awakening device in human history. Water would be poured into a top bowl, which would trickle down at a known rate to another bowl with an axial pipette inside. Thus, when this second bowl filled, its water would rapidly fall into a third closed vessel, forcing air to come whistling out through a tube, and (hopefully) waking anyone nearby.

The Best Sources for Updates and News on the Coronavirus

Ross Pomeroy - March 14, 2020

The past weeks have brought quite a change of pace – to markets, to countries, to daily life. The SARS-CoV-2 coronavirus, along with COVID-19 (the disease it causes), has spread worldwide. We are in a new normal.

Here at RCS, our mission remains unchanged: to bring you the most clear, relevant, and evidence-based science news and opinion. Of late, that means our daily updates have been dominated by the coronavirus. In our attempts to seek out the best information on the pandemic, we've noticed a variety of websites, organizations, and writers that have consistently done outstanding work. We'd like to highlight a few of them now, while acknowledging that there are many more dedicated sources also striving diligently to inform the public and arrest the viral threat. You'll find their reports regularly featured at RCS as the outbreak plays out over the ensuing weeks and months.


For daily updates, visit STAT, Live Science, NewScientist, Kaiser Health News, Gizmodo, and the Associated Press.

Three Useless Theories of Consciousness

Ross Pomeroy - March 10, 2020

Consciousness is the awareness of existence. While most would agree that we have it, nobody really knows how it arises. And we may never know. That doesn't stop academics from endlessly debating it, however.

From these esoteric debates, a lot of useless theories arise. Note: they're not useless because they're uninteresting. They're useless because they provide no meaningful mechanisms for consciousness to emerge and don't even elaborate on how these mechanisms could be uncovered. Back in 2016, Michael Graziano, a Professor of Neuroscience and Psychology at Princeton University, took aim at three of them.

Oscillation Theory states that consciousness arises from fluctuations in neuronal activity. That's basically it.

"It appeals to intuition and explains nothing," Graziano wrote.

Five Reasons You Don't Need to Panic About the COVID-19 Coronavirus

Ross Pomeroy - February 29, 2020

The SARS-CoV-2 coronavirus (causing the disease COVID-19) that emerged in Wuhan, China back in December 2019 is now spreading globally and has now been declared a pandemic by the World Health Organization (WHO). Its ascendance has already rattled stock markets, disrupted the daily lives of millions, and resulted in the heartbreaking deaths of over 4,000 people, including the 38 in the United States as of March 11th. With COVID-19's spread now picking up steam outside of China – it has now arrived in at least 100 countries and new cases are rising almost every day –  we can expect its outbreak to get worse before it gets better.

Make no mistake, COVID-19 is a grave pathogenic threat which must be taken seriously. According to the Centers for Disease Control (CDC):

More cases are likely to be identified in the coming days, including more cases in the United States. It’s also likely that person-to-person spread will continue to occur, including in the United States. Widespread transmission of COVID-19 in the United States would translate into large numbers of people needing medical care at the same time. Schools, childcare centers, workplaces, and other places for mass gatherings may experience more absenteeism. Public health and healthcare systems may become overloaded, with elevated rates of hospitalizations and deaths. Other critical infrastructure, such as law enforcement, emergency medical services, and transportation industry may also be affected. Health care providers and hospitals may be overwhelmed.

The CDC's warning is frank and unnerving. It is an impetus for sober and reasoned action. Stock up on a week's worth of frozen/canned food. Restock your medicine cabinet. Practice proper hygiene. Stay home if you're feeling sick. Avoid large gatherings if you are older, have a compromised immune system, or chronic health conditions like diabetes or heart disease.

Why Do New Disease Outbreaks Always Seem to Start in China?

Ross Pomeroy - February 18, 2020

The Asian Flu in 1956 killed between one and four million people worldwide. SARS in 2002 infected 8,098 and killed 774 in seventeen counties. H7N9 emerged ten years later to strike at least 1,223 people and kill four out of every ten of them. Now, the milder, yet more infectious COVID-19 has sickened more than 70,000 across the globe, resulting in 1,771 deaths.

All of these outbreaks originated in China, but why? Why is China such a hotspot for novel diseases?

"It’s not a big mystery why this is happening… lots of concentrated population, with intimate contact with lots of species of animals that are potential reservoirs, and they don’t have great hygiene required. It’s a recipe for spitting out these kinds of viruses," Dr. Steven Novella recently opined on an episode of the Skeptics' Guide to the Universe.

South Central China is a noted "mixing vessel" for viruses, Dr. Peter Daszak, President of EcoHealth Alliance, told PBS in 2016. There's lots of livestock farming, particularly poultry and pigs, with limited sanitation and lax oversight. Farmers often bring their livestock to "wet markets" where they can come into contact with all sorts of exotic animals. The various birds, mammals, and reptiles host viruses that can jump species and rapidly mutate, even potentially infecting humans. Experts are pretty sure this is precisely what happened with the current COVID-19 coronavirus, which is why, on January 30th, China issued a temporary ban on the trade of wild animals.

Evolution Canyon: A Galapagos in Israel

Ross Pomeroy - February 13, 2020

Professor Emeritus Eviatar Nevo, the founder and director of the Institute of Evolution at the University of Haifa in Israel, knows a thing or two about evolutionary biology, as his thousands of scientific publications will attest. Sit him down on a cool, yet sunny spring day at the base of a canyon on a slope of Mount Carmel near the University of Haifa, and knowledge will flow from his mouth like a resplendent fountain. This place in particular provides Nevo, who just celebrated his 91st birthday, with a special burst of inspiration. It's called Evolution Canyon.

It is "the best laboratory to study nature," Nevo insisted during an outdoor lecture he gave in 2018. “In a local environment, you have global phenomena.”

A layperson might stand at the base of the canyon, notice the lovely array of wildflowers dancing in the wind before them, the savanna-like, rocky slope to their left, and the lush, humid, and forested slope to their right, and think, "Wow, that's pretty." An evolutionary biologist would absorb the same picturesque scenery and think, "What a great place to explore the adaptation of organisms to their environment!"

Evolution Canyon is not only a model for biodiversity evolution, it’s also a model for adaptation evolution… speciation… global warming… host-pathogen interaction,” Nevo says.

Why Math Doesn't Reveal Hidden Predictions in the Bible

Ross Pomeroy - February 8, 2020

The controversy began with a scientific paper.

Equidistant letter sequences "Bible" and "code" found in the King James Version of Genesis.

Israeli mathematician Eliyahu Rips, together with Yoav Rosenberg and Doron Witztum, pored through the Hebrew Book of Genesis in search of hidden codes, and they apparently found some... The names of prominent Jewish Rabbis and the dates they were active were concealed within the text, pretty incredible considering that they existed hundreds of years after the Torah was written! Rips and his colleagues extracted these names and dates using the Equidistant Letter Sequence (ELS) method. Basically, they entered all of the letters of the Torah into a computer and searched for meaningful words and numbers that arose when starting at one letter and skipping other letters at regular intervals, either forwards or backwards. For example, the sentence, "He was a bad instructor" can be seen to contain the hidden word "habit" if you start at H and skip every couple letters.

Rips and his co-authors got their work published in the reputable peer-reviewed journal Statistical Science in 1994. The editors of the journal published the paper as a "challenging puzzle" to readers, not as verified account of divine religious predictions. Nevertheless, a great many people took it as the latter.

One of those people was journalist Michael Drosnin, who used the ELS method to find numerous accounts of the Bible apparently predicting all sorts of future events in concealed "code". His book, The Bible Code, became a bestseller. In it, he wrote "no human could have encoded the Bible in this way." He added, "I do not know if it is God," but insisted that some sort of mysterious intelligence was behind it.

Fungi That 'Eat' Radiation Are Growing on the Walls of Chernobyl's Ruined Nuclear Reactor

Ross Pomeroy - February 4, 2020

Back in 1991, scientists were amazed when they made the discovery...

In the eerie environment inside the abandoned Chernobyl Nuclear Power Plant, researchers remotely piloting robots spotted pitch black fungi growing on the walls of the decimated No. 4 nuclear reactor and even apparently breaking down radioactive graphite from the core itself. What's more, the fungi seemed to be growing towards sources of radiation, as if the microbes were attracted to them!

More than a decade later, University of Saskatchewan Professor Ekaterina Dadachova (then at the Albert Einstein College of Medicine in New York) and her colleagues acquired some of the fungi and found that they grew faster in the presence of radiation compared to other fungi. The three species tested, Cladosporium sphaerospermum, Cryptococcus neoformans and Wangiella dermatitidis, all had large amounts of the pigment melanin, which is found – among many places – in the skin of humans. People with a darker skin tone have much more of it. Melanin is known to absorb light and dissipate ultraviolet radiation, but in the fungi, it seemed to also be absorbing radiation and converting it into chemical energy for growth, perhaps in a similar fashion to how plants utilize the green pigment chlorophyll to attain energy from photosynthesis.

This photomicrograph depicts Cryptococcus neoformans using a light India ink staining preparation.

To learn more about Chernobyl's radiation-loving fungi, Jet Propulsion Laboratory researchers sent eight species collected from the area to the International Space Station (ISS) back in 2016, seeking to observe how the organisms would react. The ISS environment exposes inhabitants to between 40 and 80 times more radiation than on Earth. Researchers behind the effort hoped that the fungi would produce molecules that could be adapted into drugs that could be given to astronauts to protect them from radiation on long-term missions. Results of the experiment have yet to be published.

What's the Difference Between Belief in Dark Matter and Belief in God?

Ross Pomeroy - January 28, 2020

What does it really mean for something to be "scientific", and why is that label so powerful? Should we be equally confident in all scientific claims?

In his recent book, What Science Is and How It Really Works, University of Virginia Professor of Pathology James C. Zimring, aspired to answer those vital questions. He correctly recognizes that the process of science is woefully misunderstood by the general public and even by many scientists. Anchored with a keen grasp of philosophy, logic, and reason, Zimring attempted to resolve a variety of misconstructions.

A particularly thought-provoking passage came early in the book. Zimring notes that it is common for scientists to posit auxiliary hypotheses to explain phenomena that cannot be accounted for under accepted, evidentially entrenched theories. For example, when measurements of stars' velocities at the outskirts of spiral galaxies didn't jive with firmly established ideas of galactic motion, scientists argued that the universe must be full of unobservable matter that does not emit light or energy: dark matter.

That's quite a claim! Today, armed with lots of indirect observations, cosmologists estimate that dark matter constitutes 85% of the mass of, well, everything.

Humans Are Worse for Wildlife Than Nuclear Radiation

Ross Pomeroy - January 21, 2020

In the wake of the Fukushima-Daiichi nuclear disaster in March 2011, at least 164,865 people were evacuated from their homes as far as thirty kilometers away. Most have now returned, but some 40,000 people are still unable to do so, as the government prohibits lodging in areas where the annual radiation dose exceeds 50 millisieverts, roughly equivalent to three full-body CT scans.

But where humans are absent, wildlife has flourished.

University of Georgia wildlife biologist James Beasley and a team of colleagues recently set up 106 cameras in Fukushima's evacuation zone and captured more than 267,000 images of animals over 120 days. Wild boar, hares, macaques, pheasants, foxes, raccoon dogs, martens, bears, and civets were a few of the many creatures spotted. Beasley and his co-authors found no evidence that radiation exposure had harmed animal populations.

“Based on these analyses, our results show that level of human activity, elevation and habitat type were the primary factors influencing the abundance of the species evaluated, rather than radiation levels,” he said in a statement.

The Largest Nuclear Test in Outer Space Had Startling Effects on Hawaii

Ross Pomeroy - January 14, 2020

A little more than fifty-seven years ago, on July 8, 1962, a bright new "sun" dawned in the nighttime sky over Hawaii. Briefly resembling the blazing sphere of nuclear fusion that is our bright sun, this fiery burst quickly ballooned to seem as if it would consume the sky itself. It was a thermonuclear blast, 250 miles up, triggered by a 1.4 megaton fusion bomb called Starfish Prime. To date, it remains the largest nuclear test ever conducted in outer space.

Photograph of the Starfish Prime high-altitude nuclear test explosion.

U.S. government personnel with the Atomic Energy Commission and the Defense Atomic Support Agency carried out the experiment, witnessed by thousands of Americans on the Hawaiian Islands. Though Starfish Prime detonated roughly 900 miles away, the initial spherical explosion could be viewed quite clearly from the ground. The sky then lit up with artificial auroras, a result of some of the 10^29 energetic electrons released from the blast reaching and being absorbed by the atoms and molecules of Earth's mesophere. These could be seen as far away as New Zealand.  For roughly seven minutes, the night was a glorious light show, "like turning on all the lights over the Hawaiian Islands for a super-super athletic contest," the Honolulu Advertiser reported. Afterwards, the sky gradually dimmed to an eerie glow which persisted for four hours.

Starfish Prime's effects were also felt on the ground. The blast triggered an electromagnetic pulse (EMP), a result of electrons being rapidly accelerated and fleetingly forming their own powerful magnetic field. Citizens reported that almost at the very instant of the blast, radios blacked out, telephones stopped working, and thirty strings of streetlights on the island of Oahu spectacularly failed.

Higher up, Starfish Prime's effects lingered for months. Extra energetic electrons trapped by Earth's magnetic field formed their own radiation belts which damaged the internal components of various orbiting satellites. At least six were rendered inoperable over time, including Telstar 1, the first satellite to relay television pictures and telephone calls through space.

Plants Make Their Own "Carcinogenic" Pesticides, and You Eat a Lot More of Them

Ross Pomeroy - January 7, 2020

In an ideal world, humans could grow enough food to feed the world without synthetic pesticides, but that is not the world we live in. Readily arable land is limited and all sorts of fauna and flora pests incessantly assault agriculture. At this time, pesticides are necessary tools to stave off our species' starvation.

Despite pesticides' obvious utility, humans are generally afraid of consuming these mostly unseen chemicals. That's understandable, as various organizations have labeled them "toxins" or "carcinogens" and have even published lists of fruits and vegetables that contain the most synthetic pesticides, apparently so you can avoid eating them.

Rest assured, synthetic pesticide residues on food are safe in the minuscule amounts present – we're talking parts per billion. What's more, many are even less "toxic" than substances you encounter each and ever day. For example, glyphosate, the most commonly used herbicide in the U.S., is about three times less deadly than Tylenol and thirty times less deadly than caffeine.

To showcase further how misplaced our fear of synthetic pesticides is, we can perform another, oft-ignored comparison: pitting synthetic pesticides on fruits and vegetables against the "natural" pesticides that they produce in far greater quantities themselves.

The (Ultimate) Top Ten Science Stories of 2019

Ross Pomeroy - January 4, 2020

The year 2020 is underway! But before we chug along through yet another new year (and decade), let us pause and look back at the top science stories of 2019, determined by aggregating other "top science story" lists from only reputable sources.


Our methods remain the same as past years: We performed a Google search for "top science stories" lists, selecting only those from go-to RCS sources. Points were awarded to each story based on its ranking. For example, on a typical "top ten" list the #1 story earned ten points, #2 earned nine, #3 earned eight, and so on. Lists that had fewer than ten rankings were normalized to a 10-point scale. For the lists that did not rank the stories, each story earned 5.5 points, which is the average score if you add together all the digits from 1 to 10 and divide by ten.

The List:

Some Rich Parents Are Giving Their Kids HGH to Make Them Taller

Ross Pomeroy - December 31, 2019

Recently, a pediatric endocrinologist was at her wits' end, and so, she blew the whistle. The endocrinologist, who chose to remain anonymous, wrote to the radio show This American Life claiming she was "inundated" with affluent parents seeking human growth hormone (HGH) for their short, but otherwise healthy, children. The requests now constitute roughly half of her caseload, she reported. Even parents of kids whose heights are in the 40th percentile – just barely below average – have been demanding HGH.

Other doctors have previously been taken aback by this trend, which, as University of Wisconsin pediatric endocrinologist David. B. Allen told This American Life, appears to be centered in wealthier areas of the United States.

It's easy to see why. HGH treatments generally last three to five years and cost upwards of $300,000. And they do work. Studies show the average boost to height is 3.5 to 7.5 centimeters (1.4 to 2.8 inches)

Legally speaking, there is nothing wrong with parents requesting these treatments for their children. HGH may be banned in Major League Baseball, but the FDA has allowed its use in kids with growth hormone deficiency since 1985. In 2003, the agency broadened HGH's availability to kids with "Idiopathic Short Stature" (ISS), in other words, kids who are short with no clear cause. Pharmaceutical company Eli Lilly and Company provided the only diagnostic criteria, saying the shortest 1.2% of men and women have ISS. This corresponds to under 160 cm (63 inches) for adult men and 150 cm (59 inches) for adult women. ISS does not have a regulated definition, however, so doctors can legally prescribe HGH to children whose heights are well above the cutoff.

The Biggest Junk Science of 2019

Ross Pomeroy - December 17, 2019

There is never a shortage of people who abuse science, logic, and reason, whether out of cynical opportunism or simple ignorance. And so, every year, RealClearScience counts down the most glaring forays into junk science. Perhaps one day human actions will be guided by evidence and careful consideration of the facts, but this utopian dream did not come true in 2019. Here are nine examples to prove it.

9. Florida's New Board of Education Chairman Doesn't Support Evolution Being Taught as "Fact." This summer, Andy Tuck was elected to chair Florida's Board of Education, a committee that guides and directs public education in the state, from kindergarten through college. Eleven years ago, Tuck said "as a person of faith, I strongly oppose any study of evolution as fact at all. I’m purely in favor of it staying a theory and only a theory... I won’t support any evolution being taught as fact at all in any of our schools." When recently asked if his views had changed, Tuck gave a noncommittal answer, simply saying that students need to learn how to sort through information so they can arrive at sound conclusions.

8. Bizarre Fox News Segment Suggests the Metric System Is a Global Conspiracy. "Esperanto died, but the metric system continues, this weird, utopian, inelegant, creepy system that we alone have resisted," Fox News host Tucker Carlson said earlier this spring when conversing with art critic James Panero. He and Panero proceeded to spout odd, misinformed arguments against the "original system of global revolution and new world orders." Whether serious or not, the brief segment was certainly strange and full of logical fallacies.

7. Grain-Free Dog Food May Be Killing Dogs. With all of the inane fad diets, it was only a matter of time before hucksters marketed one for our pets as well. Enter grain-free dog food.

The Top 10 Websites for Science in 2019

Ross Pomeroy - December 12, 2019

Millions of scientific papers are published each year, detailing new discoveries, reviewing the state of research, and opining on important matters. But most people don't delve into daunting databases to learn the latest science news – who has time for that? Rather, they stay up to date with the help of various news outlets, which dig up and report on the stories that matter. At RealClearScience, we strive to steer you towards the best of these sources and castigate the worst. Near the end of the calendar year, we recognize what we perceive to be the leading websites for science content. Here are our picks for 2019:

Honorable Mentions:

For fantastic coverage of health and medicine, check out STAT.

Smithsonian provides tidy news round-ups each weekday with an extra dose of stories spanning, culture, geography, and history.

An Ingenious Highway Interchange Is Spreading Across the U.S.

Ross Pomeroy - December 10, 2019

When construction ended and the interchange opened in June 2009, there were groans and grumbles galore. Engineers had implemented a radical new design – the first of its kind in the United States – where Interstate 44 and Route 13 meet in Springfield, Missouri, and many drivers weren't enthused with being guinea pigs. Motorists on Route 13 were now forced to stop at a traffic traffic light, then follow the snaking road as it gently curved left and straightened out. For a fleeting few seconds as they crossed the bridge over Interstate 44, motorists drove on the left side of the road – like they were in England!* Some smoothly turned left to travel onto I-44, while those continuing on Route 13 crossed under another traffic light as they veered right and exited the interchange back on the right side of the road, their experience with the diverging diamond interchange (DDI) now concluded.

More than ten years later, the groans and grumbles are mostly gone as what was novel has now become mundane. There's also simply much less to complain about. Traffic flow has significantly improved and crashes are way down. Why? Because with a DDI there are no left turns that require drivers to cross an oncoming lane of traffic.

The Missouri Department of Transportation has now constructed five more DDI interchanges around Springfield, partly because they were 75% cheaper to build than traditional diamond exchanges. Subsequent analyses showed that they reduced fatal crashes by at least 55% and total crashes by roughly 40%.

The U.S. Department of Transportation's Federal Highway Administration also touts DDIs. They reference a study which compared DDI designs to conventional diamond interchange designs under a range of high and low traffic volume combinations. For higher traffic volumes, the DDI designs reduced delays by 15-60 percent and increased throughput by 10-30 percent.

Load More