Task summary
When a Household Bureau has found the numbering of a road has grown unmanageable and intends to renumber, they might use this paper. All we are doing in this simplest case is taking a single road, straight or curving, and assigning or reserving addresses at a rate of 400 per kilometer traveled. 200 odd numbers on the left, 200 even numbers on the right.
Such a simple concept is meant to be readily acceptable and useable by other Household Bureaus throughout Taiwan. They are certainly facing the same problem.
Advantages
With this total reservation of all possible future house numbers, not just the minimum required by law, one can be assured that, e.g., address 601 will be across the street from 600, and we can get off the bus, or park the car or ambulance with confidence, without needing to double check numbers on the other side of the street first. Of course this is taken for granted in North America, where ads don't need to add maps to addresses; no need to ask "what crossroad is it at?"
One might promote the plan as "having confidence in the future growth of the community, we thus reserve all future house numbers." However, one must also remind property owners that merely having a number reserved doesn't mean they now necessarily have permission to build on their land. Indeed, it would be best to clarify that our goal is actually not necessarily to fill the land with houses, but merely systematic numbering.
Also we know to get here we need to travel 1.5 kilometers from the beginning of the street. In a fog one need only look at one's odometer. No fancy satellite positioning navigation computer geographical information system etc. needed to locate the corner store in emergencies.
Or we see number 200. Thus we know we need a half kilometer to get to 600, no need for fun and games anymore.
No longer will the plaque of 601-1, 601-2,... accrue, necessitating periodic renumbering as the city grows. We achieve permanent addresses "built to last 1000 years".
Even if all the planning documents are lost, the parameters of the system can be reconstructed and addressing continued by just looking at a few houses' addresses.
Guidance maps
We produce a guidance map with guide numbers along the center of the road. (These guide numbers are for office use only and are not placed on signs etc.):
![[ Image: Guidance map]](images/s0.png)
Image: Shicheng St., Dongshi Township, Taizhong County, Taiwan
Household Bureau workers then use this map as a guide in making the actual interpolated address assignments. Odd on the left, even on the right, according to each area's "Road naming and addressing ordinance".
Numbering starts at the road junction, which all residents consider the beginning of this street.
Lanes are given numbers when encountered, e.g., the lanes pictured would probably be numbered 39, 106, and 148 by the workers.
With the flexibility of guide numbers, workers are empowered to decide fine details, e.g., the silly custom of avoiding numbers ending in 4, which sounds similar to "death" in some Chinese languages. (Yes, at most densities we can absorb this.)
The map is retained for use in future assignments. Even though there might be a pond next to the road now, in a hundred years it might become houses, so their numbers must be reserved now. We must even reserve along bridges, as our ambulance driver is looking at his odometer. There simply is no excuse not to "spend" those extra numbers. If the numbers get too high for comfort, the road can be divided into sections (1,2,3...), which is a subject worth a whole other paper.
Whole numbers however cannot be used for properties without actual frontage on our road. I.e., if there is a house hiding behind, not next to, number 66, then you can perhaps give it e.g., 7 Lane 68, or even maybe 66-1 etc. But you can't give it 68.
-
Production of guidance maps
In the simplest case, planners can photocopy a 1:5000 orthophoto map obtainable from the township office or the Forestry Bureau Aerial Survey Division, and along the road draw guidance numbers, e.g., (0+025K means 25 meters beyond kilometer marker 0)
K guidance number 0+025 10 0+050 20... 1+000 400... Slope usually has minor influence and can be ignored. For instance, if a two kilometer long road climbs 200 meters in elevation, its addresses only increase by 4, (Pythagorean theorem):
sqrt(2000**2+ 0**2)*400/1000=800 sqrt(2000**2+200**2)*400/1000=804
We used GRASS to make our guidance maps. See below. Actually, one does not need a computer at all. Just a ruler, a pencil, and in moments one can have a map made.
Makefile used.
-
400 numbers per kilometer
We chose 400 numbers per kilometer based on Taiwan minimal building frontage of five meters. Also each area's "Road naming and addressing ordinance" states numbers should be reserved every four to five meters, but that is just for where officials think buildings will be built later. I say reserve every five meters no matter what, eliminating the need for the "later additions sub numbers" clause of the ordinance. Should the law be changed? Well, anyways, each community's best numbering system is not necessarily exactly the same.
Five meters divided by the two sides of the road gives one house number per 2.5 meters, 400 numbers per kilometer. Rural Australia and New Zealand use 100 numbers per kilometer(A). But for Taiwan it would be more convenient to consider the whole island urban.
Limitations
In this paper we merely number a single road according to distance. We assigned lane numbers but did venture down the lanes to regulate further beyond current laws. By not being overly complex we won acceptance by the community and local Household Bureau.
Indeed, numbering individual streets this way might preclude more integrated whole city approaches, like parallel roads' addresses advancing in lockstep, but it is only when a street has become unmanageable does it come up for renumbering so we might be able to get our hands on it. Besides, the public has a deep rooted concept that proper roads' addresses must start with the number 1. So the best we can do is proceed one road at a time.
Single road addressing: "good for 1000 years". City-at-once addressing: "good for 10000 years". Sloppy addressing: "good for 10 years". P.S.: habitually changing people's addresses back and forth will one day find your Bureau facing compensation claims.
A letter from some long ago friend is returned "refused" or "no such person". He thinks you are angry or dead.
It's not like there's some national security reason to keep changing addresses.
A little GIS (Geographical Information System) in the planning stage will save a lot of GIS daily management later. What a shame city planning professors worldwide don't recognize address planning is a natural part of city planning. Of course a road need not lie within a city plan for us to number it properly. There is so much that can be done. Numbering parallel streets in parallel, or in a grid, street names coordinated with house numbers, etc. See my web pages(J).
Principles
All along we aim to make a system that fits with the public's understanding of house numbering, without computer assistance. We stay within the public's "addressing language". The system must be usable by the "man in the street" without needing a map or the help of some GIS team.
We don't go around "looking for completely usable addresses to rip up". Instead we say if a Household Bureau has already decided they must renumber, then at least do it right this time so there need not be a next time.
GIS Implementation
We used GRASS GIS(G) to make our guidance maps.
One might start with government vector maps, but we ended up
just scanning in the same orthophotomaps that are available to the
workers. We used GRASS commands including: db.execute,
db.select, i.group, i.rectify, i.target, r.in.gdal,
v.build.polylines, v.category, v.digit, v.net, v.net.path,
v.overlay, v.to.db, v.to.points, and Debian GNU/Linux(D) packages
xsane, sane, netpbm, etc.
All Free Software(F).
Conclusion and recommendations
In e.g., North America, addresses have long given reliable geographic information to the public. There are cities where even kids can tell you how to get to some address on some road. In Taiwan however we are still almost blindly spewing out addresses, requiring fancy GIS to keep track of where we put them. Let's do better.
Notes
The author is a volunteer consultant to the Dongshi Township Household Bureau, Taizhong County, Taiwan.
This plan was implemented by Dongshi Household Bureau in Summer 2005.
References
(A) Australian government Street Address Working Group: http://www.icsm.gov.au/icsm/street/index.html
(D) Debian Project: http://www.debian.org/
(F) FreeGIS Project: http://freegis.org/, Free Software Foundation: http://www.fsf.org/
(G) GRASS GIS: http://grass.itc.it/
(J) Jacobson, D. Taiwan address planning: http://jidanni.org/geo/house_numbering/