Office blind corner traffic light.

I have this idea for a little project/gizmo and I don't really know where to begin.

my office is at an intersection that people have a tendency to run into each other at. What I'd like is a simple little circuit that will have some sort of motion/proximity sensors, two, one each looking down one side of this corner. Two LEDs each look down one of the two sides of the corner. The idea would be that if both sensors detect motion (within 10-15feet of the corner) the led would light or blink for a second or two.

So if one person is approaching the corner nothing happens, but if people are approaching the corner from both sides the LED would alert them so they won't run into each other. Ideally I'd like this to be powered by a small photo voltaic.

I'm thinking that I could have some cap that charges from the PV, and discharges into the circuit a few times a second. This way it could just be hung there at the corner and forgotten about. Ideas???

Update: While a mirror would seem like the most obvious solution the way the offices are arranged at my corner there isn't really a place to hang a mirror. I've even stuck a car blind spot mirror on the small space between two of the office doors across the way from my door. That way at least I can check for traffic when I step outside my office. 

This is kind of an idea splinter and I need to make it so I can get it out of my head. (I hope I'm not the only one who gets mind splinters. Like a song stuck in your head it is an idea that you just have see realized or it will just sit there in your mind forever.)