Having worked in a business that both identified rail equipment with passive RFID and located OCR cameras for toll roads, I have to tell you that the OCR camera is probably more reliable than the RF and absolutely simpler. They're both easily fooled, but the RF reader doesn't know it was fooled.

With the trains, since the responses to the interrogation signal aren't exactly real-time, we had to do axle counts (magnetically) to correlate them to the known number of axles that had gone by to correlate which train-car was responding. Usually the train RF equipment is in a yard, too where the train is going slow speeds, too. If you had a bunch of automobiles whizzing past, responding to RFID readers, you'd never be able to tell which is which. When a car goes through the toll lane without an RFID transponder, it actually takes time to compute that it didn't respond and to know that it needs a photo and a ticket. If every car had one, you'd probably have a real problem identifying the one that didn't (though you'd still have to be able to snap a photo--because you don't have the ID any other way.)

Security-wise, RFID is as easily fooled as visual license plates--and you can steal someone else's number without actually taking their plate.

Now on the off-chance you were implying active RF, that is, transponders like in airplanes, yes these are reliable and secure. This is what I design now. Unfortunately, the lowest price ones are $2K plus and the really good ones are $20K.

Either way, this is something else on the car to break, something else to power, more RF signals to give us cancer and really no benefit.

Now, why do you think RF is better? I'm open to discuss, too.

Are you active in the car identification business?

No, I changed to avionics in Jan.

I am looking for people in the car ID business arena to start a new venture.I am sure there are several good technologies but always there is a place for an effective and cheaper one oriented to the masive market.Thanks.

Who is your market though?

Right now, the market as I see it, for electronically identifying a particular vehicle, is for controlled access to toll roads and private/semi-private areas, and AFAIK, the active transponders they use work well, and don't cost a whole lot in the bigger scheme of things.

I am thinking in public and semi-private areas.