I’m all for preventing drunken driving, but I don’t think scarlet-letter license plates are going to solve the problem. Here are a few reasons I doubt they’ll be so effective as some legislators hope:

1. Drivers will start paying more attention to the license plates around them when they should be paying attention to traffic signs and signals. This distraction could itself cause accidents.

2. In many families, two or more people takes turns driving one car. It’s unfair to subject relatives of a drunk driver to scarlet-letter license plates. This also makes the plates less useful, because no one will know whether they indicate a convicted drunk driver or just a family member.

3. If a car is swerving or otherwise behaving erratically, police should pull it over — whether or not the driver has been convicted previously. As for all the previous offenders who apeear to be driving normally, it’s unlikely that the police will be able to track them all down by their license plates and keep close enough tabs on them to prevent accidents. If convicted drunk drivers are so dangerous that police really need to see that on their cars, then those people should not be driving at all.