Every day, Americans travel on roads, bridges and highways without considering the safety or reliability of these structures. Yet much of the transportation infrastructure in the U.S. is outdated, deteriorating and badly in need of repair. Of the 614,387 bridges in the U.S., for example, 39% are older than their designed lifetimes, while nearly 10% are structurally deficient, meaning they could begin to break down faster or, worse, be vulnerable to catastrophic failure. The cost to repair and improve nationwide transportation infrastructure ranges from nearly US$190 billion to almost $1 trillion. Repairing U.S. infrastructure costs individual households, on average, about $3,400 every year. Traffic congestion alone is estimated to cost the average driver $1,400 in fuel and time spent commuting, a nationwide tally of more than $160 billion per year. Thousands of vehicles cross the Golden Gate Bridge every day. The Golden Gate Bridge in San Francisco averages more than 100,000 vehicles daily. Photo by Saketh Garuda for Unsplash Email X (Twitter)29 Facebook241 LinkedIn Print Every day, Americans travel on roads, bridges and highways without considering the safety or reliability of these structures. Yet much of the transportation infrastructure in the U.S. is outdated, deteriorating and badly in need of repair. Of the 614,387 bridges in the U.S., for example, 39% are older than their designed lifetimes, while nearly 10% are structurally deficient, meaning they could begin to break down faster or, worse, be vulnerable to catastrophic failure. The cost to repair and improve nationwide transportation infrastructure ranges from nearly US$190 billion to almost $1 trillion. Repairing U.S. infrastructure costs individual households, on average, about $3,400 every year. Traffic congestion alone is estimated to cost the average driver $1,400 in fuel and time spent commuting, a nationwide tally of more than $160 billion per year. The Purdue engineering lab has installed smart technology in three Indiana interstate highways. I am a professor in the Lyles School of Civil Engineering and the director of the Center for Intelligent Infrastructures at Purdue University. My co-author, Vishal Saravade, is part of my team at the Sustainable Materials and Renewable Technology (SMART) Lab. The SMART Lab researches and develops new technologies to make American infrastructure “intelligent,” safer and more cost-effective. These new systems self-monitor the condition of roads and bridges quickly and accurately and can, sometimes, even repair themselves. Smart, self-healing concrete Infrastructure – bridges, highways, pavement – deteriorates over time with continuous use. The life of structures could be extended, however, if damages were monitored in real time and fixed early on. In the northern U.S., for example, freeze-thaw cycles in winter cause water to seep into the pavement where it freezes, expands and enlarges cracks, which can cause significant damage. If left unrepaired, this damage may propagate and break down pavements and bridges. Such damage can be identified and repaired autonomously. At an early stage of a crack, for example, self-healing pavement would activate super absorbent polymers to absorb water and produce concrete-like material that fills in the crack. Cracks as small as a few microns could be healed to prevent significant damage by preventing or delaying the later stages of the freeze-thaw cycle.