5 ms·

The difference between a NULL entry and a sentinel value. And poorly designed systems. Anyone with a correct understanding of the problem domain would know yo

by mortov 13y ago

The difference between a NULL entry and a sentinel value. And poorly designed systems. Anyone with a correct understanding of the problem domain would know you have to cope with missing plates by indicating they are missing and not by using (many) different sentinel values. The fact each city/county/state uses a different value indicates the whole ticket processing system is a screwed up mess. The North American system of plates essentially identifying a person and not a vehicle is weird. The UK still allows vanity plates but they are bound to the vehicle (and to a current keeper - when you sell it the plates go with the vehicle to the new keeper unless you make special arrangements). I still find it odd to take the plates off a vehicle being sold and to have to get them put on to the new one. A vehicle without plates in violation of traffic/parking laws should be towed (or in some places it could be blown up as a security threat - Northern Ireland that used to be a regular event and a joy-riders post-drive fun to remove the plates and wait for the fireworks). At least if it is towed, the fines can be sorted out before the return of the vehicle rather than wasting time (and money) on a no-hope chase of some unidentifiable owner unless some schmuck happens to have a vanity plate matching your chosen sentinel value [in which case you then have the extra expense of wasting time cancelling the ticket or even wasting court time before it gets dismissed].

sbov 13y ago
In California plates stay with the vehicle. Not sure how it works in other places in North America. And sentinel values aren't just a problem of the system, but there would also be a human element. Even if you had a "no plate" option some would likely continue to write noplate. The current system might even support null values for all we know.
- mortov 13y ago
  In Alberta I had to get plates for a vehicle and had to keep them when I sold the vehicle (and the purchaser put their plates on to drive off). There are even regulations about how long you can have different province plates if you move leaving you technically with 2 plates for 1 vehicle (I think you're supposed to return the other plate to the original province but is more complex if you are moving around for short term work contracts of a few months and them coming back before the plate expires). I just figured this is how people end up with license plates on their wall from their first vehicle etc. However this is another aspect of my point - there is no clear uniformity on the relationship and handling of vehicle registration, plates, ticketing and enforcement. When things are poorly defined, you get inconsistent implementation and Bad Things(tm) happen as a result. Considering just the wasted postage alone, thousands of dollars of public funds were wasted sending out obviously stupid and invalid tickets - totally avoidable if someone had stopped and thought about what they were doing. Enforcement systems like this are always in danger of running away as a result and some schmuck being bankrupted or jailed (if states allow that) despite being able to demonstrate conclusively that they have done nothing wrong and are not responsible for any of the tickets. Public bodies are not good at admitting they are operating a fundamentally flawed system and it is always easier to ignore the small numbers of victims of their failure and hope no-one else notices. It does not take a lot of research to find examples of flagrant miscarriages of justice in these sorts of situations.
  - BuildTheRobots 13y ago
    > I just figured this is how people end up with license plates on their wall from their first vehicle etc. I always assumed other people ended up with a plate on the wall in the same way I did; by removing them from the car after your X drove it into a cliff-face and wrote the vehicle off.
maxerickson 13y ago
Vehicle registration is done at the state level and vehicles are often driven (by someone permanently moving) or sold across state lines. So it probably makes more sense to have a driver keep their proof of tax payment than it does to transfer it around with each sale.
freehunter 13y ago
The plate situation is even weirder in Michigan (not sure on other states). I owned several cars with the same plate, and even bought a Toyota 4Runner (which is a truck) with the same plates. When I bought a pickup truck though, I had to get new plates. Plates are registered based on vehicle type, and in Michigan SUVs are classified as station wagons, which is a type of car (in England I believe they're called estate cars) not a type of truck. Pickup trucks are different, and require a new plate.

by mortov 13y ago

sbov 13y ago

In California plates stay with the vehicle. Not sure how it works in other places in North America. And sentinel values aren't just a problem of the system, but there would also be a human element. Even if you had a "no plate" option some would likely continue to write noplate. The current system might even support null values for all we know.

mortov 13y ago
In Alberta I had to get plates for a vehicle and had to keep them when I sold the vehicle (and the purchaser put their plates on to drive off). There are even regulations about how long you can have different province plates if you move leaving you technically with 2 plates for 1 vehicle (I think you're supposed to return the other plate to the original province but is more complex if you are moving around for short term work contracts of a few months and them coming back before the plate expires). I just figured this is how people end up with license plates on their wall from their first vehicle etc. However this is another aspect of my point - there is no clear uniformity on the relationship and handling of vehicle registration, plates, ticketing and enforcement. When things are poorly defined, you get inconsistent implementation and Bad Things(tm) happen as a result. Considering just the wasted postage alone, thousands of dollars of public funds were wasted sending out obviously stupid and invalid tickets - totally avoidable if someone had stopped and thought about what they were doing. Enforcement systems like this are always in danger of running away as a result and some schmuck being bankrupted or jailed (if states allow that) despite being able to demonstrate conclusively that they have done nothing wrong and are not responsible for any of the tickets. Public bodies are not good at admitting they are operating a fundamentally flawed system and it is always easier to ignore the small numbers of victims of their failure and hope no-one else notices. It does not take a lot of research to find examples of flagrant miscarriages of justice in these sorts of situations.
- BuildTheRobots 13y ago
  > I just figured this is how people end up with license plates on their wall from their first vehicle etc. I always assumed other people ended up with a plate on the wall in the same way I did; by removing them from the car after your X drove it into a cliff-face and wrote the vehicle off.

maxerickson 13y ago

Vehicle registration is done at the state level and vehicles are often driven (by someone permanently moving) or sold across state lines. So it probably makes more sense to have a driver keep their proof of tax payment than it does to transfer it around with each sale.

freehunter 13y ago

The plate situation is even weirder in Michigan (not sure on other states). I owned several cars with the same plate, and even bought a Toyota 4Runner (which is a truck) with the same plates. When I bought a pickup truck though, I had to get new plates. Plates are registered based on vehicle type, and in Michigan SUVs are classified as station wagons, which is a type of car (in England I believe they're called estate cars) not a type of truck. Pickup trucks are different, and require a new plate.