I think that's more of a function of the relative difference between the sizes of your vehicle and the other vehicle, not the absolute size of the other vehicle

I think that's more of a function of the relative difference between the sizes of your vehicle and the other vehicle, not the absolute size of the other vehicle. The relative size is a big factor in why mixing bikes with cars is so deadly. The other one, of course, is relative speed. Years ago I got my CDL and there was a multiple choice question to the effect of what is the safest speed to drive. Three of the answers were all relative to the speed limit and the correct answer was relative to other traffic: the safest speed is the speed of the cars around you, or zero relative speed.