I do not like the idea of the proposed green light cameras that Alberta has just given the go ahead for.
The problem I have is simple - as a driver, if I'm coming up on an intersection as the light turns yellow, I have a snap decision to make - try to stop, or try to go through. I've seen more than enough cases where trying to stop would create a panic stop situation, and likely as not, would end up with the car behind hitting me. The second option is often to push it a little and accelerate through the intersection. This is a split second decision - based entirely upon my immediate judgment of the situation.
What this does, much like the Red Light cameras do, is create a situation where a driver's decision is now subject to penalty, and is only measured along a single vector of consideration. I'm not objecting to nailing people who speed, or run red lights - but rather the problem is the fact that these things can be set overly aggressively, thereby penalizing drivers who are making legitimate safety decisions as they drive. (and yes, the yellow light period is a gray zone - and that's what I'm most worried about - I don't care about solid green or red situations, but I do care about the yellow light - there's just too many circumstances where the decision has to be made in the moment, and a camera simply cannot capture that context)