The product you seek is called "Higate the Snowgate" and are marketed by North Products, Inc. in Bismarck, ND.

They don't work well on trucks due to visibility issues and it is my understanding that curbs wear them out in short order.

No, that is a different idea; but I do appreciate the response. You misunderstand.
The Higate you refer to is a large fixed blade surface that is attached to buckets to guide and pack snow into buckets, not blades.

My idea is to attach a small deflector that temporarily restricts the "flow" of snow off the end of a blade and then lays back after passing a driveway.

As for wear, there shouldn't be any more wear than there would be for any blade since it becomes part of the blade. And if that part does wear, it is much smaller than the entire blade and could be replaced at a lower cost.

Okay, now I follow you. The extra verbage in response to Hyenuf helped. I like this idea but the camera/reflector apparatus is not going to work. If we are dealing with a large snow drift or blizzard conditions the markers will not be visible. We need to think of another way to mark the start and stop points. A simple sensor system comes to mind which could be placed on both sides of the drive. One sensor tells the deflector to open the next to close. Now we need to look at the deflector. How big do imagine this would be or, mathmatically speaking, how big does it have to be to dam the snow for a distance of 15 feet while pushing a 1 foot drift. We might be running into some problems here.

At first I thought about GPS. But then, snow storms could easily block the signals. For cities where the snow doesn't get over a couple of feet deep, the reflector idea would probably work.
But in areas where they can get four feet of snow at a time, you are right, I wonder if a city would consider allowing a peg to be driven into the road with a RFID in it. That way the snow plows can run over it, the sensor transmits a signal signifying the beginning of a driveway a certain distance away. That way a truck running on a highway at 65 mph will time the deflection differently than a truck running 15 mph on an urban side street.

The RFID could also transmit the address at that driveway for emergency vehicles to use.

bkeene12, Regarding how big would the deflector need to be.
That is a difficult question because snow is sticky and packs, while slush flows freely. A 12" deflector on the end of a relatively large plow, let's say 36" in height, would probably stop the flow of snow to the point of stopping the truck. Being the equivalent of making the blade flat and packing the snow in front. Guessing, from personal experience working with farm tractor and blade to clear snow in Michigan.
While varying degrees of slush would only dam up slightly and flow around the end. The percentage of slush to snow would largely influence how much flow or packing was involved.

As was suggested above, a pair of embedded RFID devices would seem like the best answer.