09 Novem ber 2007 / 18 Aqrab 1386
Last spring I pointed out that Kabul now has an address system in the form of Google Earth coordinates. On Wednesday I saw a presentation of USAID’s Land Titling and Economic Reform Assistance (LTERA) project of assigning addresses on streets. They way they do flexible, universal addressing is interesting: choose one end of a block to start from. Addresses on the right will be even, addresses on the left will be odd. Measure distance to doorways from the beginning of the street. Assign addresses according to the nearest meter-distance from the beginning. If a doorway is 21.7 meters from the beginning and it is on the left, the address is #21. If it is on the right, it is probably #22. Given the size of meters, no doorways will appear within the same meter-distance on the same side, so this system assigns unique numbers very quickly; and if new buildings are built, their addresses can be inserted.
Following along similar lines, one could also assign post-codes via Google Earth coordinates. Here I show a chunk of central Kabul that should be familiar to anyone who has worked in the city.
Google Earth gives coordinates to the 1/100th of a second. That is more information than we need for this process. Here I have gridded the area in two-second increments, and you can see that they are already very fine divisions:
So, imagine that a bunch of post offices are built in this area. I will propose five, and give their coordinates:
| Post Office | Google Earth coordinates | Post Code |
| Chahr Rahye Ansari | 34d 31’57″N, 69d 09’55″E | 43157-90955 |
| Ch. Haji Yacoub | 34d 32’09″N, 69d 10’03″E | 43209-91003 |
| Ch. Shah Shahid | 34d 32’21″N, 69d 10’16″E | 43221-91016 |
| Ch. Shir Pur | 34d 31’58″N, 69d 10’32″E | 43158-91032 |
| Wazir Akbar Khan | 34d 32’07″N, 69d 10’52″E | 43207-91052 |
So what I did was take the latitude and longitude, strip off the first digits, and collapse them together. This gives a unique post-code to each post office, even if they are quite close together. Furthermore, by adding the 3 and the 6 to the head of each part of the code, you have the geographic coordinates of the building itself.
Or, another way of doing it might be to use the official abbreviation for the city, and then you could shorten the numbers even further.
| Post Office | Google Earth coordinates | Post Code |
| Chahr Rahye Ansari | 34d 31’57″N, 69d 09’55″E | 3157-0955 |
| Ch. Haji Yacoub | 34d 32’09″N, 69d 10’03″E | 3209-1003 |
| Ch. Shah Shahid | 34d 32’21″N, 69d 10’16″E | 3221-1016 |
| Ch. Shir Pur | 34d 31’58″N, 69d 10’32″E | 3158-1032 |
| Wazir Akbar Khan | 34d 32’07″N, 69d 10’52″E | 3207-1052 |
All of Kabul city happens to sit within 34 degrees North and 69 degrees East, so you could drop the first two digits of each, and just associate the post-codes with the city name to get unique coordinates.