What is up with today's motorists? I now do a lot less cycling than I used to, and I select my routes and times/days of travel very carefully.

Personal opinion: Between cell phones, map displays, and those damnably, dangerously distracting touchscreen controls, I think too many motorists are multitasking, leaving less attention for pedestrians, cyclists, and even sometimes other motorists. Add frustration with congestion and general aggressiveness driven by "I'm late!" thinking.

EDIT: This was an all-too-common side entry collision. Expect to see a lot of more of those as the badvocates and traffic segregationists get their way, preventing us from positioning ourselves where we will not only be seen, but also be visually relevant to motorists.