Wrong Way Sensors (before another senseless death)

I have worked in ITS for nearly 14 years and during this time I have seen a number of very innovative sensors that monitor road conditions, traffic speeds, and various other conditions in the traveling public.  I have yet to see a sensor that can worn a driver that they are traveling in the wrong direction while in their vehicle.  While I've been immersed in this industry, I've seen signage and inductive sensors that are placed at entry points on the roadway to prevent this, but I think it would be nice to integrate it with an audible alarm in the passenger vehicle.  This in-vehicle sensor seems like it should be easy to deploy as most vehicles have the option of a compass, along with a navigation system.  If you were to tri-angulate GPS, In vehicle Navigation and direction of travel from the compass, it seems like a no brainer.  This idea just came to me as I watched my wife go to the funeral of a very dear friend recently here in Colorado.  Call it coincidence, but I have now personally known 3 people who have been killed in the course of just driving a vehicle down a highway and being hit head on by a driver heading the wrong direction.  These Incidents are senseless and in most cases, deadly.  We have in vehicle navigation systems that can tell us our direction of travel, why can't we simply utilize these to point out the proper direction of travel to the driver.  Good old fashion ingenuity says to me this should be easy to implement and no doubt as functional as a seatbelt when it comes to saving lives.  Having been in the industry for years it seems very doable!  Let's hope someone has already thought about it, because this senseless tragedy need not happen!