Ok, I'm brave. My guesses:... for a moment.
You are going to shoot traffic at night, and you do not want too much motion blur. What camera settings you guess you need - aperture, shutter speed, ISO setting?
All this sort of reminds me of my Rolleicord VA I had a long time ago. It had pictograms on the camera back predicting the EV value of different lighting situations. And of course the camera could be set to an EV value directly which was maintained while you varied the shutter speed/aperture.>
This particular discussion is more about:
- there is a way to predict exposure based on incident light in the scene, and that helps to know how much eV to dial in the camera overriding the reflective metering