If you are in America, the chances are that one in 75 of passengers will be killed by a car - most of those by someone else’s car. The weight of their machines has a cost, because it makes the roads more dangerous for everyone else. For every life the heaviest 1% of SUVs or trucks saves in America, more than a dozen lives are lost in smaller vehicles.
Each year cars kill roughly 40000 people in America - and not just because it is a big place where people love to drive. The country’s roads are nearly twice as dangerous per mile driven as those in the rest of the rich world.
Weight is to blame. Using data for 7.5 million crashes in 14 American states in 2013-23, for every 10000 crashes the heaviest vehicles kill 37 people in the other car, compared with 5.7 for cars of a median weight and just 2.6 for the lightest. The situation is getting worse.
In 2023, 31% of new cars in America weighed over 2.27 tonnes, compared with 22% in 2018. The number of pedestrians killed by cars has almost doubled since 2010.
Although a typical car is 25% lighter in Europe and 40% lighter in Japan, electrification will add weight there too, exacerbating the gap between the heaviest vehicles and the lightest. The Ford F-150 Lightning weighs around 40% more than its petrol-engine cousin because of the battery.
In 2022 France introduced a surcharge on new vehicles of €10 (US$11) per kg over 1800kg.
In 2023 Norway began taxing car buyers at a rate of NKr12.50 (US$1.17) per kg over 500kg.
Yet even if all those things were to change, consumer preferences are so strong that adjustments to fuel-efficiency standards would probably not be enough. That suggests another line of attack: as well as making cars lighter, you can make accidents rarer and less deadly.
Mismatches between big and small cars on America’s roads are not new.
In the 1960s the 635kg Mini Cooper shared the road with the 2270kg Cadillac Fleetwood and the 2500kg Lincoln Continental. But the issue of vehicle "compatibility" did not gain public attention until the rise of SUVs in the 1990s.
Between 1990 and 2005 the market share of such vehicles grew from 6% to 26%, pushing up the weight of an average new car from 1540kg to nearly 1860kg.
As suburban soccer moms traded in their station wagons for Ford Expeditions, many felt safer. But the extra protection provided by heavier vehicles comes at the expense
of others on the road.
The average new car in America weighs more than 1995kg (compared with 1500kg in the European Union and 1180kg in Japan). Vehicles weighing more than 2300kg accounted for 31% of new cars in 2023, up from 22% five years earlier.