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The long road ahead: Improving transportation infrastructure

November 21, 2016

ASU researchers paving the way to roads that last longer, cost less and keep safety and sustainability at the forefront

On Aug. 1, 2007, 13 people in Minnesota never made it home from their evening commute. There wasn’t a bomb, a mass shooting or a natural disaster. These 13 deaths and 145 injuries were the result of a failed system.

That system — one that we use and take for granted every day — is our transportation infrastructure. Minnesota’s I-35W Mississippi River bridge had a structural failure and abruptly crumbled to the ground, taking cars and lives down with it. It was a sobering reminder that the roads, highways and bridges millions of Americans rely on daily are not indestructible. In fact, much of our transportation system in the United States is unfit to carry the load it bears.

About 40 percent of federal highways and major roads in the U.S. are not considered to be in good condition. Nearly 70,000 of the nation’s bridges are considered structurally deficient, while more than 98,000 are functionally obsoleteStructural deficiencies are characterized by deteriorated conditions of significant bridge elements and potentially reduced load-carrying capacity, but do not necessarily imply safety concerns. Functional obsolescence is characterized by bridges not meeting current design standards, such as lane width or number of lanes, relative to the traffic volume carried by the bridge., according to the Federal Highway Administration.

Our roads are in desperate need of a revamp. Researchers at ASU are paving the way to better transportation infrastructure that lasts longer, costs less and protects the environment as well as human safety.

I-35W bridge collapse

The I-35W bridge collapsed suddenly, killing 13 people and injuring 145. Photo by Tony Webster/Flickr

Rubbery roads and sustainable cement

ASU engineering professor Kamil Kaloush tests and recommends improvements to pavement performance. His team found that materials for roads can be made better by including a special ingredient derived from cars themselves — recycled tires.

Producers process the tire scraps and grind them into a material called crumb rubber. The rubber reacts as an enhanced elastic component when mixed with asphalt cement. The mixture forms rubberized or asphalt rubber pavement. This is one of the projects Kaloush oversees as the director of the National Center of Excellence on SMART (Sustainable Materials and Renewable Technologies) Innovations at ASU.

Rubberized pavement has many benefits. Just like the egg in a recipe for chocolate chip cookies, rubber makes roads much more resistant to cracking. That translates to less maintenance over time, a smoother and safer ride for drivers.

“Reduced deformation and cracking translates into road-user benefits such as better ride quality, less fuel consumption, lower maintenance frequencies and safer roadways,” Kaloush said.

The asphalt-rubber mixture is cost-effective compared with conventional pavement and is better for the environment. Rubberized pavement is also stronger and better performing than traditional types, so it can be applied as a thinner layer, using less material. Because it uses recycled materials, rubberized pavement requires fewer natural resources to produce. Its smoother surface also reduces particle emissions from tire wear and tear, resulting in better air quality.

Because rubberized pavement is thinner than traditional types, it stores and gives off less heat. Researchers have shown this can help mitigate the urban heat-island effect, which happens when buildings and paved surfaces absorb and retain heat. That results in cooler temperatures for everyone, on and off the road.

ASU engineering professor Narayanan Neithalath is also developing new materials for infrastructure. Some of his research focuses on longer-lasting concrete and cement for roads, bridges, tunnels and dams.

Portland cement is the most commonly used material for these projects, but it lasts only 20 to 25 years and has an environmental footprint like a fleet of Hummers. Neithalath wants to replace Portland cement with a material that lasts twice as long and requires fewer resources to manufacture — call it the Prius of the concrete world.

Kaloush said effective transportation infrastructure is a balancing act of durability, safety and efficient mobility of people and goods. In the future, those challenges will be compounded by the clashing of two semi-trucks — climate change and a rapidly growing population.

Sensing danger

The I-35W bridge in Minnesota was originally designed to carry approximately 60,000 cars per day when it was built in 1967. By 2007 when the bridge collapsed, traffic had increased to about 160,000 cars per day. This heavier load, plus a design flaw that went overlooked for years, led to the bridge’s demise.

I-35W was a steel-truss bridge, a type known as “fracture-critical.” Like a line of dominoes, if one piece of the bridge fails, the whole structure will collapse. There are more than 12,600 bridges of the same design still in use all over the U.S., and they are growing older and weaker each day.

In 2015, the I-10 bridge to Los Angeles was toppled by a 100-year flooding event. The desert-dwelling structure was never built to withstand so much rain. But as climate change brings about more extreme weather, our roads, bridges and other infrastructure will be tested in unprecedented ways.

“A huge number of bridges are dangerous, as far as an engineer would view them. Some engineers would refuse to cross them or go underneath them, they’re that dangerous,” said ASU professor Tim James.

James is an economist who focuses on transportation infrastructure. He said there haven’t been significant improvements made to the U.S. interstate system since it was built in the 1930s. For comparison, most airplane fleets have been replaced three times over since our road system was built.

The main challenge with revamping roads is a lack of funding. Most money for the road system comes from taxes on gasoline. The federal tax is a fixed amount of 18.4 cents per gallon. That hasn’t changed in more than 20 years, aside from a 0.4 cent increase in 1993. States charge an additional tax that averages about 23.5 cents.

“The tax on gas has been the same for 25 or 30 years, and it’s miniscule,” James said. “Compared to European levels, it’s like peanuts.”

It will take a major increase in funding to repair the roads, but building more durable and less resource-intensive infrastructure can help keep costs down. We can also work to make our roads safer — a benefit that goes beyond dollar value.

Building brainy bridges

Neithalath’s team is hoping to advance a new area of infrastructure technology that borrows a technique from the medical field. Just like an electrocardiogram monitors the rhythm of a patient’s heart, Neithalath wants to develop sensors that monitor the health of our highways.

Some roads across the U.S. already use sensors. For example, the bridge that replaced Minnesota’s I-35W is self-monitoring, with 323 fiber-optic sensors embedded in the concrete.

But Neithalath’s team is working on a new, more accurate type of fiber-optic sensor. These are coated in chemicals that react with the pavement to measure markers of deterioration. Sensors detect the presence of chlorides and sulfates, then transmit their findings back to engineers.

“For example, if you’re putting a lot of salt on your bridge and it starts to go through and corrode the steel, my fiber-optic sensors will tell me how much salt is inside the concrete,” Neithalath said.

St. Anthony bridge

The new St. Anthony bridge in Minneapolis has 323 sensors embedded in the concrete. The 504-foot structure is also the only bridge in the U.S. to be illuminated by LED lights. Photo by Ruin Raider/Flickr

Before sensors, the only way to find out a road’s health was to sever it open and peer between the cracks, or wait for a catastrophic failure. This new approach is like preventative medicine. As soon as the sensors detect vulnerability, they diagnose the problem and alert engineers that repairs are needed. Engineers can then order more tests or decide on a course of treatment.

Catching corrosion early on is especially important as more people move into cities. With a growing population, it becomes difficult to shut down roads and bridges for major repairs. With this in mind, ASU researchers want to build infrastructure that puts safety and sustainability on cruise control.

“We can use less resources, we can make bridges last longer and we can make them less risky,” Neithalath said. “Sustainability is a collaboration of all these different things.”

Allie Nicodemo

Communications specialist , Office of Knowledge Enterprise Development

480-727-5616

 
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'We should not be in the business of extinction'

ASU researcher co-authors paper published in journal Science on gene-drive tech.
Gene-drive kit available for cheap online causes stir among scientists.
November 21, 2016

ASU researcher enters ethics debate over cheap, gene-editing technology, co-authoring paper in journal Science

A cheap and radical tool that enables geneticists and researchers to edit genomes easily by removing, adding or altering sections of the DNA sequence is causing a stir among scientists.

The CRISPR-Cas9 uses gene-drive technology, which promotes the inheritance of a particular gene to increase its prevalence in a population, and it’s available on the internet for about $300.

It raises the question: Could biohobbyists flood the natural world with organisms concocted in basement labs? Science fiction — via works such as “Frankenstein,” “Jurassic Park” and “Westworld” — tells us that’s not something we’d want.

An Arizona State University researcher has stepped into the conversation, co-authoring a paper published in the journal Science, advising care and providing a roadmap to using gene-drive technology.

“What folks would be worried about, potentially, is you could genetically modify an organism with this gene-drive system with the expectation of reducing an individual species, like say a population of mosquitos — but it drives that species to extinction,” said James Collins, co-author of “Precaution and governance of emerging technologies” and Virginia M. Ullman Professor of Natural History and the Environment in the School of Life Sciences at ASU.

“Or you could set out that as your goal. Then you begin to get on a very slippery slope. … We should not be in the business of extinction.”

Collins also is co-chair of the National Academy of Sciences' Committee on Gene Drive Research in Non-human Organisms: Recommendations for Responsible Conduct, a panel of 16 experts who released a lengthy report in June on the topic.

It was a rare instance of ethics beating technology out the door.

“What you want, ideally, is to be ahead of the release of a new technology and have thought about what the ethical, legal and social implications are that of technology so that you're not in a situation of trying to close the barn door after the horses are out,” Collins said. “So with gene drives we are in that advantageous position of being ahead of technology and having this kind of report in place.”

Emma Frow is an assistant professor with a joint appointment in the School of Biological and Health Systems Engineering, and the Consortium for Science, Policy and Outcomes.

“There’s a reasonable history of science being aware of the implications of the technologies and trying to take steps to put in safeguards for their own research and work,” Frow said. “This type of gene-drive technology is causing particular discussions and interest within the scientific community because it’s radically different than what previous technologies could do.”

Previous genetically designed organisms were designed not to survive out of the lab or on their own, she said.

“Gene drives are explicitly designed to spread,” Frow said. “It’s almost a different approach.”

'This isn't a natural process'

People have tampered for thousands of years with horses, crops and pets, but it was through a natural process. This isn’t a natural process, said Andrew Maynard, a professor in the School for the Future of Innovation in Society at ASU and director of the Risk Innovation Lab — a unique center focused on transforming how we think about and act on risk, in the pursuit of increasing and maintaining “value.”

“Effectively, what we’ve got is a vastly expanded tool kit for playing around with genetic codes,” Maynard said. “Now we can reprogram and modify genetic codes far faster, far easier and far more sophisticatedly than we have ever done before. The thing that is unique about gene drives is the ability to force that genetic change through subsequent regenerations. In a way, we’re borrowing again from nature, so we’re not doing something that has never been seen before in nature, but we’re co-opting it and using it in a way which you don’t see occurring naturally.”

Gene drives can speed nature up and also create aspects never seen in nature before.

“You could create novel traits that would be very long time occurring through a process of natural selection or never get there through the process of natural selection,” Collins said. “So this enables you to move beyond certain kind of boundaries that are tougher to overcome through natural selection. With natural selection, you work with the variants you have at hand. These techniques allows you create variations that you don’t have at hand.”

The technology isn’t so much new as it is different from what has come before, according to Collins. It falls between the cracks of the Environmental Protection Agency, the Food and Drug Adminstration, and the U.S. Department of Agriculture. There’s no consensus on how to handle it.

A report from the Office of Science and Technology Policy at the White House on new forms to genetic modification, including gene drives and how to think about all of this, is due out soon.

Risk panic vs. innovation thrill

The struggle in using the science is between two concepts — risk panic and innovation thrill — both of which were demonstrated by the Manhattan Project building nuclear weapons during World War II.

Risk panic is irrational fears paralyzing development of new technologies. It’s the superego of the two — being so scared of results that the tech is mothballed. Los Alamos scientists weren’t sure if the bomb they were building would set the atmosphere on fire or not. They agreed the project could not be allowed to continue if this were the case. (When the numbers proved that chance was less than 3 in 1 million, they went ahead.)

The second concept is innovation thrill. It’s the id of the duo. Go ahead and do it, just because you can. Robert Oppenheimer was a proponent of the notion. “He talked about this notion of innovation thrill, and you argue about what to do only after you have your technical success,” Collins said.

Neither is better than the other, Collins and his co-authors said. What’s needed is a predefined roadway, with checks and balances.

Too much precaution can stifle science, Collins said. But if you think about the ability to take an organism and completely change the nature of that organism, you can see a future rife with unintended consequences.

Locusts swarm and obliterate crops. What if you reprogram them so they never swarm? Sounds great, but what happens if that swarming is essential to other ecosystems? What if the swarm is bad for people but good for the broader environment?

“If you take something out of the natural environment which has evolved over hundreds of thousands of years, and more than that, there are likely to be some unintended consequences,” Maynard said. “If you go back and have a look at how we’ve used species to deal with environmental problems — 'if you have a rat problem, you bring in cats' approach — we’ve seen that time and time again, when you bring in an organism to deal with a problem, that organism becomes the next generation’s problem. Then the question is: As we begin to genetically engineer organisms, do we have the same problem? Does it become the next generation’s problem to deal with?”

Obstacles as safeguards

One caveat is this is not easy to do. The likelihood of a bright hobbyist creating some horror of a lifeform that actually survives is tiny.

Frow has judged the International Genetically Engineered Machine for years. It’s an international competition for students interested in synthetic biology. Student teams are given a kit of biological parts to build and test biological systems in living cells, ranging from bacteria to mammalian cells. These are undergrads in well-funded institutions with academic support, and they still struggle, Frow said.

“It’s really hard,” she said. “It’s pretty unusual for teams to come in with proof that what they’re thinking about works.  We’re talking about smart undergrads. It’s not trivial for them to do this. … Right now it’s still really hard.”

Another obstacle to unleashing a science-fiction nightmare is the ecological modeling.

“We need to be a little bit careful here when we talk about the danger of this technology,” Frow said. “It’s not one mosquito or one fruit fly escaping the lab. It’s unlikely to propagate through the entire population. Scientists are trying to figure out what portion of the population you’d have to release.”

There are safeguards in place at the university level, Collins said, codes and guidelines of ethics and principles.

However, there’s nothing equivalent at the national level, no consensus on how to handle the technology.

“The national framework is uncertain at this point, as far as the gene-drive technology is concerned,” Collins said.

The national committee Collins co-chaired was a mix of natural scientists and social scientists interested in the ethical, legal and social implications of the technology. They came to the conclusion that scientists should seek input from stakeholders and then turn their proposals to the public for deliberation.

“You want to get input from the stakeholders and from the public as you’re going along, relative to constructing the initial hypothesis and designing these experiments, and — in the case of these gene drives — whether or not you want to actually release them into the environment,” said Collins, who has served on similar government panels.

Human history is fraught with ideas that seemed really great at the time, Maynard said.

“What we’re seeing now with technology and innovation is that we don’t have enough time to clean up the mess,” he said. “That’s especially true with gene drives, where we can move so fast that the consequences can potentially overtake us before we deal with problems that emerge. … You just say, ‘We’ll create an even better, more powerful gene drive to correct the problems of the previous gene drive.’ Where does that end?”

The paper’s examination of the National Academy’s report recognizes we need to be ahead of gene drives, but it’s also a really important technology. Paralyzing worry about consequences can’t hold us back.

“Those are, I think, really important points,” Maynard said. “It’s encouraging to see the science community beginning to think critically about what you can do early on to make sure that a novel technology is responsible and beneficial. The bigger challenge is how do you go outside the science community?”

Scott Seckel

Reporter , ASU Now

480-727-4502