Identify specific vehicle & counting

openCV isn't that hard...

Lots of beginner books also, don't let the math scare you, most of it you can figure out by testing and see.

The math is just there to make people feel smart.

You'd use IR, all the time - IR ring light and filter on the camera

It would be cheaper, if that is a factor...

Potentially more robust also.

But go which way interests you ! They're both interesting ideas

;)