Nah, motorists.org is just a clearinghouse for the studies. I know that is a group that would fight that, but they didn't conduct the studies. Studies were conducted by tv stations, transportation research organizations, universities, other countries, etc.
My own former employer, the Transportation Research Board, conducted a study that was intended to prove they worked, but the evidence didn't support it:
"The TRB's National Cooperative Highway Research Program Synthesis 310, Impact of Red Light Camera Enforcement on Crash Experience-A Synthesis of Highway Practice was meant to support the use of red light cameras, but in reality it undermined the credibility of the devices. The authors attempted to support the devices by speaking of the "preponderance of evidence" that the cameras equaled safety. However, any time this was stated, the authors were honest enough to admit that none of the information was conclusive."
Anyway, this is neither here nor there, except that I remember reading all sorts of things about accidents actually increasing at such intersections. (But apparently not in Dallas.) I wouldn't be surprised if the severity of the accidents was lessened, though ... I didn't read those studies up there, and I have no idea if they conclude that injuries are up or down. Which would really be the more important statistic.
So, this is a roundabout way of saying that I agree that you can't really be all that specific with the SCOR. It kind of is like that Shared Space concept outlined in those articles:
"...Psychologists have long revealed the senselessness of such exaggerated regulation. About 70 percent of traffic signs are ignored by drivers. What's more, the glut of prohibitions is tantamount to treating the driver like a child and it also foments resentment. He may stop in front of the crosswalk, but that only makes him feel justified in preventing pedestrians from crossing the street on every other occasion. Every traffic light baits him with the promise of making it over the crossing while the light is still yellow...."
I'm not saying this will work everywhere, including a ski hill -- I don't know -- but as was said earlier, you can't legislate every little possible thing into the code.