It should be a relatively simple matter in principle to dial a license plate number into a cellphone and be connected to any cellphone number associated with that plate. The problems would be with privacy. Once you start linking disparate databases, it's easy to find out things that people would rather keep private. If we had some reliable institution, say a govenment that people could trust, this might work.

Another way to do the same thing is to have LED crawl strips that could display any text you want. The one in front of your car would have to display mirror image text so that it could be read in the target's rearview mirror.

All of the complicated procedures in the suggested methodology, are achieved today, by a simple "flashing the lights". Why can we not consider it a courteous "request to pass" after all?

As we strive to create tools to make our lives better, we should also remember to keep them simple.

Enabling communication always makes things better!

I like the LED screens (send a message to your window via a bluetooth cell phone), but here is another idea:

Use a radio, but...

Add direction-finding: transmissions are played back from appropriate speaker(s) in a surround sound fashion.

Add distance-finding: distort and/or mute distant transmissions (weak signals). Turn a knob to select the range/sensitivity you want based on traffic conditions. For example, in traffic jams you may want a 10 ft range, while on open freeway, 1000 ft.

Now when you cut someone off and they are to your right-rear, you can hear a nice, loud complaint from that driver, seemingly coming from his direction.

On the other side of the coin, you can reward curteous drivers with a verbal Thank You a lot more effectively than with a hand wave.

Nate betterdifferent.com

Frequently the psychological effect of being in a car is equivalent to being anonymous in a position of power. This is mitigated to an extent by the license plate but this is a clumsy device and ID is usually available only through official mediums. Some form of direct communication in the same way that aircraft can be directly communicated with might make the average driver think twice before displaying antisocial or dangerous behavior. Instead of the primitive instruments of flashing lights or written signals, the simple direct communication of a speaker system and a cell-phone connection with a rapid system for nearby drivers or the police to speak directly to the driver would be a major adjunct to safety and lawful behavior. Of course the technical details would have to be worked out but they are not impossible.

Man this is all so big brother!

Technical issues aside, any means you can find to communicate with me than doesn't enter my car (flashing the lights on YOUR car) is one thing, but penetrating that sphere of privacy (somehow dialing MY cellphone -- assuming I have or want one in my car) is another.

Now beyond that, have you ever pondered how many people KNOW you're coming up to pass, and regardless of how tactfully or untactfully you handle it, THEY think you shouldn't be going faster (just like some people think THEY ought to be able to force their communications inside your car), so they're going to sit and poke in front of you regardless, to make you behave like they think you should. So ANY communication or means thereof is meaningless. You may just have to be ~patient~ until you have a different opportunity to pass.

You don't need new regulations when all you have to do is be a civilized human being. For the person prone to road rage, if he now has the ability to talk to you in your car, this likely will only ENHANCE his road rage!

Even aircraft communication is fairly voluntary, I remember flying a Cessna during a flying lesson and seeing another aircraft approach from my 12 o'clock, and that pilot not making the radio call he was supposed to make to alert traffic in proximity to him. It really pissed off my instructor.

The flash-to-pass is a perfectly satisfactory convention, maybe everyone just needs to be instructed in the use of their headlights when getting their license (because it seems you only learn of flash-to-pass via osmosis, not a DMV handbook).

Regarding "flash to pass"...The reason the DMV manual doesn't mention it and instructors don't tell you about it is probably because it is illegal. I know it is illegal in Wisconsin. I suspect it is elsewhere.

When a truck driver flashes his lights, it's to communicate to other (truck) drivers that it's okay to pass or turn or change lanes. This works because other (truck) drivers understand the signals, and because (truck) drivers pay close attention to what other (truck) drivers are doing, as indicated by the use of lights, turn signals, and horns.

What 4-wheel (car) drivers do often has no bearing whatsoever on what their signalled intentions are. The most sophisticated signalling devices aren't a substitute for an alert driver who knows what he's doing, and pays attention to what others are doing. Perhaps the solution is stricter licensing requirements (already required for professional drivers in the form of the CDL), and universal mandatory periodical driver re-training.