this doesn't surprise me. I've read in a new york times article about 10 years ago, that when cyclists cycle without helmets on the average distance between them and cars around them is greater than when they do wear helmets.
Buses, cars, trucks have often traveled behind me at a following distance of barely a meter behind my bicycle. Stopping suddenly would have high risk of death.
Cars and trucks have clipped my handlebars.
Cars turn in front, oblivious to cyclists existence. That or they have a complete lack of awareness: a cyclist needs braking distance like any moving object.
Not to mention opening doors or the drivers who think it's funny to harass those not in a car.
I don't ride much anymore