Human drivers are fucking awful. I don’t understand why everybody here is assuming that the self-driving car must have done something strange to cause this.

This, but also, human drivers do similarly awful things like stop at the end of a long acceleration on-ramp when they should have been accelerating to match the speed of traffic they are attempting to merge into.

It's biased because all commenters are human drivers who think they can handle that kind of situation. We often don't realise how much risk we take on every day while at the wheel.

What percent of drivers are involved in a collision while merging? I imagine it's miniscule. Rarely deadly.

I banged up my mum's car doing exactly this the first year I got my license. Was a little nervous and in a hurry, saw an opening and went for it. Car in front of me did not see the same opening. Bang.