In most cities where I have been, there is traffic congestion and speeds are usually low, most accidents are fender-benders. It is inconvenient to get into bump

In most cities where I have been, there is traffic congestion and speeds are usually low, most accidents are fender-benders. It is inconvenient to get into bumps, but not life-threatening. On highways, at least in the US, the average speed is 65-70mph. You'll see some drivers doing 90 or more regularly. At 90mph, if you are in a compact car, if a truck or SUV hits you, there is a high chance of major injury or death. You are right there are no cars coming from the other direction, but i've seen cars get bumped from the back, then spin. I've seen cars bumped from the corner by a driver who clearly did not check their blind spot, and the small car spins. The small car is at a huge disadvantage, especially in the US where there are massive trucks and SUVs all over the highway. There is also bullying by bigger cars/trucks on highways where they expect small cars to get out of the way and/or drive defensively.