Two scary accidents in 20 years, both partially or wholly my fault.

1) Following a car through an intersection on a wet day and I hadn't tightened my brake cables for a while. I was tailgaiting in his right rear blindspot, because the light was yellow and I wanted to get through. I thought we were through, then he suddenly turned right, into the gas station on the far side of the intersection. I couldn't stop in time with my wet, slack brakes, and had to turn right with him, but it was just before the driveway and my wheel couldn't climb the curb at at that narrow angle and I had to dive onto the sidewalk. Looked at my left hand and saw my pinky bent 90 degrees sideways at the second knuckle. Thought it was broken, but when I flexed it, it popped into line. It had been dislocated.

Lesson:
- beware the right hook - don't be cruising in the blind spot
- leave more room to brake on wet days
- maintain your equipment

2) I had to turn right onto a street with streetcar tracks, then immediately left. So for the first turn, I waited for a gap in traffic, then swung out into the middle lane where the rails were as I entered the road, merging into traffic, and crossing the first streetcar rail at a very oblique angle. My front wheel dropped in the slot and I went down. Traffic was close enough behind me that it had to brake. Lots of bruises but no other injuries.

Lesson
- cross streetcar tracks at right angle if possible.
- be alert crossing if you have to do it at a narrow angle - remember to hop or at least unweight the front wheel a bit to help it float over the gap
- be sure there's plenty of room when merging lanes

I've had a few others as well, but they were more embarrassing or predictable, than dangerous: Two falls when learning clipless riding, and one fall on ice. I don't ride on ice anymore.