Studies show that we have a tendency to perceive the distance of oncoming traffic as greater than it really is. Furthermore, when the distance increases, we become even worse at estimating it.

Studies also show that we have a tendency to underestimate the speed of oncoming traffic. When the vehicle is far away, it is nearly impossible to judge its speed with any degree of accuracy.

In general, it is easier to accurately estimate the speed of traffic on a crossing road than that of traffic moving straight towards you.

Additionally, smaller oncoming vehicles (such as mopeds and motorcycles) seem farther away than larger vehicles.