I almost got hit the other day walking in a crosswalk. The first car stopped, and the car coming up behind them must have thought they were stopped for no reason, because they veered around to the left lane at full speed and blew right past me. I had to jump back to avoid getting hit. Come to think of it, it's not too different from the scenario where the Gaudreau's got killed.
People have zero patience. They also just forget that pedestrians and cyclists exist. There is a level of impatience and blood boiling anger that comes from sitting in traffic and it makes drivers put human life in jeopardy. Even sometimes when people see you they do things that are insane. In day to day life, outside of a vehicle, these are probably all nice people, but behind the wheel they become something else.