I'd appreciate any advice anyone has about how to better avoid this situation, as I'm not totally sure whether I did everything I should have here.
There is a particular point on my commute home where I have to turn right off of a major arterial road onto a side road, and then take a left off of the side road soon after. The arterial road is a particularly hazardous one for cyclists (very busy with 2 lanes each direction + center lane, speed limit of 40 mph, in practice many cars travel at speeds of 55+). It has bike lanes, which I don't love, as I think it encourages people to fly through there rather than taking care. The 2-lane side road that I turn onto there has much lighter traffic, and is much narrower, so I really can't share a lane safely with a car on that road. That means that I have to merge left into the traffic stream on the side road from the bike lane on the busy road (also, I have to do this to prepare for my upcoming left soon after the intersection). For the most part, I haven't had problems doing this, as there is not much right-turning vehicle traffic there. I try to be cautious and signal my intent, but it seems to throw a few drivers for a loop that I was in the bike lane on the main road and now am in the single main lane on the side road. I certainly don't turn right at the same time as a car or anything like that, as obviously that would set up a conflict over the lane space and I think would put me technically in the wrong since I would be the one merging left. Instead, I turn right, signal and merge left, and then signal and turn left while moving to the center line. Most drivers seem to figure out my intentions just fine, and either wait behind me until after I take my left or pass on my right (since I'll be near the center line as I prepare for my left turn).
Well, yesterday it didn't work out that way. A motorist, who was driving very aggressively in general, came roaring around the corner soon after I made my right turn onto the side road, and ended up behind me in the lane. He seemed surprised that I was there, and slammed on his brakes and came to a complete stop behind me (stupid, and too fast a turn, but whatever...). So, I just stuck my left arm out, and proceeded as normal to move towards the center line and prepare for my upcoming left turn. Then, VERY unexpectedly for me, the guy passes me ON THE LEFT by flooring it and gunning his engine from a standstill. He crossed totally over into the oncoming lane and came within inches of hitting several cars that were waiting for the light in the opposite direction. Then, he swerved back to the right immediately in front of me, totally cutting off my path (I'd have been hit hard if I'd already been in the middle of my left turn, but fortunately I was watching him because he seemed to be an aggressive driver). I immediately braked and turned hard to the right to avoid getting hit, and ended up wiping out on the pavement because of the sudden evasive maneuver. The guy saw me go down, paused briefly in the road up ahead, and then floored it and took off, without even bothering to ask if I was okay (I picked myself up very quickly, not wanting to be on the ground in the road there, so maybe he figured I wasn't hurt at all). I did end up falling on my wrist, which hurts a little bit now, so I wasn't totally fine, and I broke the mount for my bike computer.
I'll admit I was pissed, and gave the guy the finger as I picked myself up. And I didn't have the presence of mind to get his license plate number. But thinking back on this, is there anything I could do to prevent this situation from happening in the future? I'm wondering whether the fact that this happened soon after a right turn might have contributed to his surprise/poor handling of the situation, as I try not to assume malicious intent. I'm just not sure what else I can do to avoid something this, since I did signal clearly and had completed the merge into the traffic lane BEFORE he made his right.