Personally, I feel quite confident in my ability to judge whether it's safe to make a left turn. If you're not, I don't think you should be driving a car. Still, this may prevent accidents on occasion. However, if you rely too much on the system to protect you, you could be setting yourself up for disaster at an intersection that doesn't have the system installed or is out of order. There's also the possibility that another car approaching the intersection doesn't have a working unit and is thus invisible to the system. It also might fail to see pedestrians, animals, rolling trashcans, etc.

The city I live in just installed a camera system on some newly reconstructed intersections. The cameras are linked to a computer that "reads" the traffic in all directions at the intersection and adjusts the signals to work with that traffic.

The traffic engineer told me it will respond to motorcycles and pedestrians, two things the good old traffic loop system has trouble "seeing". He says the cameras can be fooled by larger birds and wind blown debris though. I'm wondering how well they work in heavy snowstorms. . . .time will tell.

It's really kind of interesting how well it works. I noticed that while approaching the intersection on the secondary street when there was no traffic on the primary street the light changed green in my direction before I got to the intersection so I did not have to stop. Quite an improvement over the old loops where 15 to 45 seconds passed before the lights changed.

This idea would work if all drivers use their turn signals. It is my experience that many (if not most) drivers do not. In places with dedicated turning lanes this would be worth a try.