In the UK, the Highways Agency has set up speed cameras that record the license plate numbers of speeding drivers and flash them up on a screen but do not issue penalties. Trials have shown that drivers get the message quicker when they see their own registration shown below the speed limit.
It’s similar to the mirror effect in psychology, where a person is less likely to do something they think is immoral if they can see themselves doing it in a mirror. Some shops have started using mirrors as a detterent to theft because of that, and it works.
Another similar idea is highlighted in this NY Times article. It talks about a new website called Platewire.com where you can post the license plate number of any dangerous drive you come in contact with.
Just like with any consumer reports or epinions review type website, information starts getting spread around more easily, so reputation becomes more important. People start realizing there is more than just tickets to worry about, there’s public perception.
I think they’re fantastic ideas, using human psychology and incentives instead of just issuing tickets and collecting money.