RTC. Road Traffic Collision. We used to say RTA, (Road Traffic Accident) but someone, somewhere decided the word accident meant that nobody was to blame and potentially posed a legal nightmare, so the word collision was put in its place. That way, no matter what hit what (bike vs. pedestrian, bus vs. car, cyclist vs. manhole cover), someone could be held accountable, although I'd like to see what a manhole cover has to say for itself in court.
The word incident could have been used but I guess that sounds too innocuous for the purists.
