As it turns out, people are stupid.
Truer words have never been spoken. People are stupid and you can't fix stupid. You'd think they'd weed themselves out eventually, but as it turns out, we're all people. And we're all stupid. We're just stupid at different times.
I've nearly run into the back of someone at a stop light when they started rolling forward and then suddenly slammed on the brakes because they didn't see a car coming into the intersection. I was glancing around checking for traffic I might have been concerned with and nearly ran into the back of him because I just assumed he was going to continue rolling forward like the hundreds of others before him I had been behind at other intersections.
A single moment of inattention and a single false assumption nearly caused a wreck. I was stupid. We're all stupid. We all need some engineered help against stupid from time to time. A sensor that detects an impending crash with something right in front of me would have helped. Lots of cars have these things now. That's an engineered solution to a moment of stupidity.
Not everything can be fixed with engineered solutions, but we can't assume modifying behavior is a fix-all either. In fact, I would give behavior modification a far less chance of success given how random and clueless we meatbags are.
So I vote for more engineered solutions, not less. But the solutions need to involved some human behavioral analysis as well. I mean who in their right minds couldn't have predicted that passing motorists would see these count down times and use them to speed through intersections? And who wouldn't have predicted that this would leave to an increase in accidents on average? Duh. That should have been taken into account and a different solution should have been investigated.
All that said, I also feel like we need to define some acceptable limits here. I mean we can't go making every single intersection 100% secure. If some accidents are happening at an intersection, let's talk about the *rate* and decide if that's just an acceptable rate or not. The fact that there are accidents or that accidents are happening a little more often now than they were before is a little meaningless without numbers to compare to. I find that we have FAR, FAR too many laws and regulations trying to bring fatalities and liabilities and accidents to near zero already.