This week, trapped Under a stagnant warm air mountain, known as Hot dome, The Pacific Northwest has a taste of the future.
On Sunday, as the temperature reached 105 degrees, the concrete under Interstate 544 on the outskirts of Everson, Washington, began to play the role of concrete when it gets very hot: expansion. By 5 pm, the asphalt on it had softened and cracked, leaving a thick hump joint in the two lanes. In the southern city of Portland, Oregon, a road on the north side of the city was blocked around a pothole, causing the authorities to close the surrounding streets.
As the heat wave subsided, the craze continued to hit. Amtrak reduced the speed of the trains served by its Cascades, fearing that the high temperature would deform the tracks. The power cable melted on the Portland tram, and service was cancelled on Sunday and Monday. The local light rail system also ceased because its overhead copper wire sagged at a high temperature of 120 degrees and became unusable.
“As extreme weather becomes more and more common, we realize that as an institution, we need to become more adaptable to climate change,” said Taylor Graf, a spokesperson for TriMet, which operates the light rail system.
Scientists have long warned that as climate change. Heat waves, floods, storms and hurricanes that have lasted 100 or 1000 years will become more common. Now, the extreme weather in the Northwest and the subsequent cracks, depressions and delays remind people that the country’s underfunded and undervalued transportation network is not yet ready for the future.
Aging roads—in some cases 50 or 70 years old—cause this problem. Over time, water and other debris have seeped into the space between the concrete slabs that make up the road. When concrete expands under extreme heat, it pushes upwards. Morgan Balogh, assistant regional administrator responsible for maintenance and operations at the Washington Department of Transportation, said: “When an area that does not experience high temperatures often comes in, this brings us many challenges.”
A little-known fact complicates the situation: roads and railways are constructed differently in different places. Many highways in the United States are paved with asphalt concrete, which is a mixture of gravel, gravel and sand called “aggregate”, and a soft black “binder.” Binder is the remnants of crude oil, kerosene and other products refined; its quality depends on where and how it is manufactured. In arid and hot deserts like Arizona, engineers use hard adhesives that can withstand high temperatures. In Seattle, the adhesive can soften at lower temperatures because it should not become so hot. This is part of the reason why the normal summer temperatures in Phoenix have caused severe damage to places like Bellingham, Washington. Similarly, the overhead wires in the Phoenix light rail system are calibrated to withstand up to 120 degrees of heat.
Hussein Bahia, professor of civil and environmental engineering at the University of Wisconsin and head of the school’s modified asphalt research center, said that under extreme high temperatures, asphalt will soften and behave a bit like peanut butter. He said, put it in the oven, it will become a kind of “mud.” Constant high temperatures on roads not built for heating can cause potholes, pitting, and bumps. The bumps can cause the car to lose control. When it rains again, they increase the possibility of water skiing. Overheating is particularly detrimental to roads because it reduces the road’s ability to withstand strain and spreads heavy loads on its surface.
As the regional climate changes, it is difficult for road builders to keep up. Shane Underwood, associate professor of civil, architectural and environmental engineering at North Carolina State University, said some state agencies have begun to incorporate updated climate data into their formulas for selecting asphalt mixtures. But he said that no one has predicted a hotter future yet. The roads built today could have been used for decades, but they may not be ready to withstand the climate of the future. He and his colleagues estimate that climate change may increase road maintenance costs by billions of dollars each year.
“It is absolutely important to integrate what science says about what temperature will look like into decision-making,” Underwood said. Organizations must strike a good balance between a limited budget and the cost of different road materials.
At the same time, in Washington, DC, politicians are finalizing a new infrastructure deal — and Has deprived it of its main climate proposal.As the Pacific Northwest continues to watch How many people died in the record-breaking heat, It is not clear whether the person in charge understands what is about to happen, or whether he is willing to learn from the recent past.
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