America's roads are crumbling, but we can make them sustainable

America's roads are crumbling, but we can make them sustainable
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A bipartisan push is underway in Congress to add infrastructure to the next round of COVID-19 recovery. As with other efforts already undertaken to help our struggling economy, it is likely to bridge political divides and get it to the president’s desk — especially since it is an election year.

But we can’t go forward on infrastructure without looking back.

In the face of a massive economic disaster in 2009, the U.S. initiated the largest public works project since Eisenhower’s Interstate System — the American Recovery and Reinvestment Act (ARRA). But now, a decade later, ironically, our roads have only marginally improved.


So, as Congress seeks to invest once again in infrastructure, we should ask: why did ARRA fail to significantly improve our roads and what can we learn from it?

When drafting ARRA, Congress sought promptness. Six months after the ink dried, America already embarked on 2,000 transportation projects. In the short term, we saw excellent results: The percent of structurally deficient bridges dropped from 9.3 percent in 2009 to 8.7 percent in 2011, while highways with good ride quality rose from 58.4 percent to 60.5 percent in the same period. 

But in the long-term, America saw mixed outcomes. Though bridges continued to improve after 2009, highway road quality peaked in 2011 and then declined. As of 2018, a large majority of our roads are in poor or mediocre condition.

Moreover, ARRA couldn’t meet demand for long-term projects. Its TIGER program, for instance, sought “long-term transformative investments,” yet provided only $5 billion in response to thousands of requests for funds totaling $152 billion.

But the need for long-term investment can’t be the only takeaway from ARRA.

Over the next century, our infrastructure must cope with new, unprecedented stresses due to climate, structural inequality, and recently, the economy. Therefore, we need to be sustainable in every sense of the word: Today’s investment must sustain future generations as they face unique economic, environmental and social challenges.

That means thinking creatively, not complacently.

Believe it or not, many transportation agencies use the same techniques to maintain roads over their life even as material prices and technologies change. Failing to adapt to these evolving conditions leads to spending more for worse outcomes. This approach simply isn’t sustainable: as COVID-19 has taught us, situations that once seemed certain often change rapidly and unexpectedly.

Rather than spending expediently and repetitively, there needs to be prudent investment in solutions that give us the best long-term performance. 

Our research at the MIT Concrete Sustainability Hub has found that states can save tens of millions of dollars over several decades with a “mix of fixes” — essentially a strategic combination of long- and short-term pavement improvements that account for the uncertainty in future conditions. 

It’s not just how we build, but also about what we build with. Currently, government procurement processes have become stagnant, with conventional strategies chosen over more sustainable alternatives.

Some states pave with just one material, which decreases industry competition and increases prices. Opening up the construction market to greater competition will spur innovation and lower costs. 

Fiscal sustainability begets environmental sustainability. The same strategies that optimize spending — a mix of fixes and materials — also reduce excess fuel consumption of vehicles by improving inefficient, poor quality roads.

Though not widely discussed, road quality exerts a significant environmental toll. Our research identified 1 billion gallons of excess fuel consumption over 5 years on California’s highway network. That’s about 3 percent of all fuel consumption on those 50,000 miles of roads during that time period.

As the nation improves its roads, it should also reimagine how it uses them. For example, we can implement bus lanes that decrease travel times in cities like Boston and HOV/express lanes that already reduce congestion and increase throughput in Washington State.

However, for America’s roads to be truly sustainable, they will also have to address social challenges, like structural inequality. Currently, highways, not local roads, receive the bulk of federal funding. As a result, 30 percent of local roads possess poor quality in comparison to 5 percent of highways (a disparity that our phone app, Carbin, has mapped). That impacts Americans directly.

These are the roads we live on, and unfortunately, on which many die. Though fatalities inside vehicles have decreased recently, pedestrian and cyclist fatalities are rising — and occur more frequently on local roads. It’s in our nation’s most vulnerable communities that these fatalities occur at a higher rate. 

Again, it’s all about how we choose to allocate our resources and now’s the time to spend equitably on safer, more efficient roads rather than neglecting vulnerable communities.

There isn’t a silver bullet for our nation’s ailing roads. Fixing them will require investments in a variety of proven and innovative approaches. But unlike in 2009, our investments can’t just respond to today’s challenges—they must meet the needs of future generations. Every aspect of sustainability must now dictate how we spend on our infrastructure. If not, it will be another transformative opportunity lost. 

Dr. Jeremy Gregory is a research scientist in Civil and Environmental Engineering at the Massachusetts Institute of Technology and is executive director of its Concrete Sustainability Hub.