One way to fight climate change by reducing emissions of heat-trapping gases is to use electric vehicles (EVs). Tesla is the early leader in their production and sale, but other car makers have entered or will enter the field, with GM committed to making only such vehicles by 2035.
The environmental advantages of cars and SUVs powered by electric batteries are clear. There are no tailpipe emissions (or even tailpipes). Electric engines are more efficient than gasoline or diesel engines, as shown by their much lower waste heat, so you get more miles for each energy input even if fossil fuels are used to generate the electricity. What’s more, we are increasingly generating electricity by wind and solar, so fossil fuels play a diminishing role in moving the car.
This doesn’t mean that EVs are carbon neutral. At present, fossil fuels are used in the mining of and smelting of iron, in converting iron to steel, in shaping the steel, and in assembling the car, whether it’s a traditional car or an EV. In addition, making the extensive battery packs used by EVs requires energy and poses environmental challenges. All in all, however, EVs are much more environmentally friendly than traditional cars and SUVs.
Because EV cars and SUVs have environmental advantages, many people think that EV trucks, including the large 18-wheelers that carry intercity freight, would also be a good idea. They have the same advantages over current trucks as EV cars and SUVs have over their counterparts. Nevertheless, using large EV trucks to move intercity freight is a bad idea because rail is a superior alternative.
A class 8 truck, which is the kind I’m talking about, is defined as weighing at least 33,000 pounds all by itself. Fully loaded with freight, it’s permitted to weigh up to 80,000 pounds. Such heavy vehicles do enormous damage to roads. A government study was published in 1976 by the Federal General Accounting Office (GAO) entitled “Excessive Truck Weight: An Expensive Burden We Can No Longer Support.” The study showed that an 80,000 pound 18-wheeler rolling over a bit of road does 9,600 times the damage of a 2,000-pound car with two axels.
The reason for the enormous difference is that, as the study found, road damage equals the difference in weight taken to the third power. So, if one vehicle is 2 times as heavy as another, it does 8 times as much damage to the road, because 2 to the third power (2 × 2 × 2) equals 8.
Unlike those used in the GOA study, current cars and SUVs don’t weigh only 2,000 pounds on average. The average weight of all the vehicles that most of us drive today – cars of all sizes, small trucks, and SUVs – is about 4,000 pounds. Since 4,000 pounds is two times the weight of 2,000 pounds, the vehicles that most of us drive do about 8 times as much road damage as the ones considered by the GAO. So, instead of an 80,000-pound truck doing 9,600 times as much damage as the average (2,000-pound) car, it now does “only” 1,200 times as much damage (9,600 divided by 8) as current cars and SUVs.
But wait! The average car is driven only about 13,500 miles a year, whereas the average class-8 truck is driven almost 5 times as far, and therefore does 6,000 times as much damage to the roads each year (5 × 1,200) as the average car or SUV. Adding heavy electric batteries would make matters worse, unless long-haulers reduce the weight of their cargo. No wonder people say that Chicago has only two seasons – winter and road repair.
Freight trains are a superior alternative. They’re much more energy efficient than trucks. Fuel-efficient trucks can move a ton of freight 130 miles with each gallon of fuel, but trains can move that ton 480 miles per gallon. Train tracks and beds are designed for the weight of trains, thereby reducing the cost of infrastructure repairs. Traffic congestion, potholes, accidents, injuries, and deaths on the highway will all be reduced when fewer large trucks are damaging roads and competing for space.
In addition, trains can run on electricity without the extra weight, cost, and environmental damage associated with the production and use of EV batteries. The train can be supplied with electricity through wires in the third rail connecting the train’s engine to an electric generating plant. Some passenger trains, such as the Long Island Railway, have long been electric. And electric motors already move our freight trains. Their diesel engines just generate electricity for the electric motor that moves the train.
In sum, the move to electricity is good, but intercity freight should move by electric rail, not by EV trucks.
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