Here’s a perfect example of how you should never build up too much speed while overtaking behind somebody, because you may find yourself in need to slowing down immediately.
We’re not exactly sure what happened to this E39 BMW 5-Series, apart from the fact that it should have been able to stop after its driver managed to avoid a frontal collision with an incoming Daewoo. He either didn’t have sufficient visibility to start the maneuver (for if he had, it’s reasonable to think he wouldn’t have risked an accident) or simply assumed his car was fast enough to complete the maneuver in time, which has its own ignorance to it.
What we’re most curious about is why did it then run into the back of that van? We know the car with the dash cam was doing around 125 km/h (77 mph) when it got passed by the 5er, so perhaps we’re dealing with speeds upwards of 140 km/h (86 mph) – and that’s before any brake pressure was applied.
Perhaps it’s just an illusion, but the van doesn’t seem to be moving at too slow of a pace, at least not initially. This makes it seem as if the driver of the BMW did have both room and time to apply the brakes and slow himself down enough so as to not run into the car ahead.
What obviously happened is the exact opposite of that, so maybe it just looks like he could have stopped when in fact it was already too late.