Thursday, 3 May 2012

The OCD, Random Walk Post of the Year


I'm basically a pretty simple man; my thoughts, when not of wife, son, family, or job, tend to wander towards politics, sports (mostly baseball), travel, and numbers.

This random walk ties at least of few of those together.

We recently returned from a trip to Hawaii and California, which was my home state for most of my adult life.  Our rental car had the California licence plate 6YSE842.  Not terribly interesting. At least to the real "99 per cent" of people.

But it got me to thinking.

California, like many states, issues its licence plates in alpha-numeric order.  Very soon, the state will exhaust its supply of plates of "6" series (i.e., 6ABC123), and roll into the "7" series.  I am not sure when the final allocation - 6ZZZ999 - will be stamped and issued from Sacramento, but if it hasn't, it will in all certainty be in 2012.

Also, like many combinations - and area codes come to mind - there is a finite number of number/letter combinations.  For six digit plates, that's 26**3 (for the ABC portion) x 1000 (for the 123 portion).  That's approximately 17.5 million combinations, though I suspect some embarrassing three-letter combinations are not made.

When I was born, California had just reached the end of its famous "black plate" run (yellow letters/numbers stamped on a black, steel base).  ZZZ-999 was issued in late 1969:

CA 69 #YXA 306
Sample California "Black Plate" from 1969

These plates are considered highly collectible to classic car owners, largely because in 1970, when the next series was issued, the state no longer required owners to surrender their plates to register.  Hence, a car that had been purchased during its run (1963-1969) and has remained in the Golden State, will likely still sport its California bona fides to prove it's truly a "California car." 

In 1969/1970, with all 17.5 million combinations issued, the state swapped the order from ABC-123 to 123-ABC, and issued its iconic blue and gold set:

CA 69 #194 AAI
The Plate that Made California Famous

Incidentally, this is the format/colour that the licence plates took when I was a small child living in Southern California.

This change bought Sacramento some time, but by 1982, the California DMV had again reached its limit, and faced a formatting challenge.

The solution was to revert back to the ABC-123 formats used between 1956 and 1969, but with a twist.  A seventh place-holder was introduced at the start, and the 1ABC234 format was born.  The base plate of gold on blue was kept, but the state had crossed the seven-digit rubicon.

CA 82 #1AAX608
The Plate that Saved Sacramento

This numbering format has been in place ever since.

So, between 1956 and 1969, California used an ABC-123 scheme.  Approximately 13 years.

From 1969 to 1982, a 123-ABC scheme sufficed. Again, about 13 years.

The state, needless to say, has continued to add people, and thus, drivers.

The '1' series (basically, an entire ABC-123 run) was exhausted by 1988.  Six years.

The '2' series concluded with 2ZZZ999 in 1992.  Four years.

My first car was registered in February 1993, 3BXE321.  I purchased another vehicle and registered it in October 1995; its plate was 3TSR355.  I rolled a "4" series plate (4DNT473) in June of 2000, and a 5 (5EXE236) in November 2003.

CA 93 #3AQY717
My Very First Car Had This Rather Boring Format

I've done some quick calculations, and the state basically is exhausting its runs every 3.7 years or so.  Put another way, in just about 11 years from now, the final seven digit plate - 9ZZZ999 - is going to be stamped.

I may be alone in being curious to see what scheme the DMV are going to try.





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