After being tailgated for a dozen blocks or so by a big black pick-up with tinted windows, a thought occurred to me: as I saw him cut-off two other vehicles in less than a block of the double-lane road we were all travelling on, I wondered about a world where the three of us could present our combined assessment of that person's driving in some sort of public forum. This led me to further speculate on a system that went beyond public shaming, where enough poor assessments could affect someone's insurance rating or the number of points on their driver's licence.
At its most basic, the system would combine RFID tags and readers, and some simple appliance that would provide little beyond Internet access. As a practical aside, maybe the system could be partially financed by asking people to buy the optional appliance (that would include the RFID reader), while the RFID tag would be universally deployed in the licence plate. In other words, rating how others drive would be optional, but everyone within a certain radius would be able to rate your driving regardless.
As I see it, a city-run, Internet-accessible system would allocate a certain (small, at least initially) number of slots to each citizen on a periodic basis (say, monthly). It would have to be signature-based, but it would also need to scale well -- I'm thinking at least a million users (municipal in the sense of Ottawa, in other words... Manhattan would need a different system entirely) -- so I'm wondering if it would have to be session-based also, as opposed to some sort of asymmetric system that piggy-backs off the driver's licence renewal. Either way, the goal would be to make it somewhat difficult to spoof another person's identity, keeping in mind that cryptographic complexity is at odds with the 'simple' appliance I mentioned earlier.
With these slots, a person could choose to rate any other identifier that their RFID reader is picking up at that moment. Obviously, the more complex the rating system, the less safe it would be to operate while driving, so I'm thinking that each identifier around you (i.e., other drivers) is assigned a number, and once you press that number, you then press '1' through '5' to rate that person's driving. (And maybe you have a different set of buttons for the rating system, so that it's clear that '1' is poor or '1' is stellar -- colours introduce other problems... maybe smiley faces and frowns -- since no two surveys are ever the same in that regard.)
So, to go back to my earlier example, if I pick up and rate that truck on my rating system appliance, and the two others who were cut-off do the same, this city-run system would pick up three ratings of one identifier's driving with very similar timestamps. At this point, some sort of reputation system would qualify each of our ratings based on a number of factors: how often we submit ratings, how often those ratings are corroborated, both by drivers around us, and by other drivers at other times of the day, how other drivers rate our driving, the number of years we've driving, how many accidents we've had, etc. I'm going beyond the basic system with some of these factors, but the idea is that you would vary the number of slots each person gets, and the factors considered by the reputation system over time, studying whether there were any appreciable benefits to introducing any of these complexities.
Because one of the many unspoken costs behind this idea is the potential for abuse. It's fine to speculate on a secure, city-run system, but if we tie in too much information, or use the rating that pops out to impose serious penalties on people, the system would become too valuable a target to reasonably secure. However, if it's used to augment the systems we already have in place, I think it could work: if I knew that running this yellow light could get me my second poor rating of the day (and a strongly-corroborated, poor rating, if the intersection's busy), I'd probably think twice about doing it.
And that's where the real strength of this system would be: you would want there to be very little incentive to damaging a person's reputation, either by falsely submitting many uncorroborated ratings of others in their name, or by falsely submitting many poor ratings on their driving. The idea would be that identifiers that repeatedly came up as poor drivers, as rated by many different people, both at the same time, and over a significant period of time, would have that reflected in a permanent record of some sort, keeping in mind that the most recent year's record would carry more weight than the one before it (i.e., much like accident records now).
As a side-note, this is my hundredth post; and in just six short years! ;-)