selecting the codification system -...

47 Street Addressing Manual

3 Selecting the Codification System

Objective and anticipated results

Codification consists of identifying streets and numbering entryways. It is a system that makes it possible to give a name or a number to each neighborhood, street and building in order to facilitate location. The codification system selected should respond to the following principles:

• It should make it possible to rapidly codify all streets until they are “named”; streets that are already named keep their name, but also receive a number which is inscribed on a street plaque.

• It should allow for rapid identification (for example, a taxi driver should be able to rapidly identify the zone in which the street is located).

• It should be adaptable to different types of towns and urbanization (structured or non-structured neighborhoods) and take into account the rapid development of certain neighborhoods.

• It should be possible to be realized progressively, according to available resources (financial and human).

Responsibility and development Executor(s): The Street Addressing Unit and a consultant. Decision: The Project Manager. Duration: The selection of a codification system can be made quickly, but must still be approved by the project manager.


Methodology

I – Decide on a street identification system

- names - numbers.

II – Section the town into “units”

- by neighborhood - or according to the official administrative sectioning (neighborhoods,

districts, municipalities, depending on the town). III – Decide which way streets should run

- based on two large axes that cross close to the town center - or based on some clear landmark such as the seashore, a cliff, a border,

etc. IV – Select the system for numbering buildings

- sequential - metric.

1st Task – Decide on a street identification system The first stage consists of determining the global identification principle. The choice is between:

- allocating names - allocating numbers.

1 – Giving streets names: Principles: - Each street is given its own name. It can be the name of a famous person, a country, an historic date, a plant, etc. Advantages: - Names are more eloquent, and therefore easier for users to remember. Disadvantages: - Names do not help in locating places/buildings, as there is no rule governing their geographical location. - Searching for a name for each individual street is a long exercise, requiring consensus.


2 – Allocating street numbers: Principles: - A number must be allocated to each “unit”, then to each street. The street number begins with the code number for the neighborhood in which it is located. For example, a street with the number 2.017 is the street bearing the number 17, located in neighborhood 2.

Advantages:

- It is a simple system, and can be rapidly put in place. - It makes identification easy since the neighborhood in which the street is located can easily be identified. - For the population as a whole, it is often easier to recognize numbers than letters.

Disadvantages:

- Numbers may sometimes be very long and therefore difficult to remember. This may often result in confusion. - It is not always possible to keep the same code from one end of a street to another if the street crosses several “units”.

To simplify the process, it is recommended that a numeric system be applied to begin with. If necessary, the two systems can be mixed at a later point in time, with certain major streets being named and also numbered. Streets that are already named will keep their names, but are also given a number. After this, streets will need to be named, beginning with major streets. To help select the names, a catalogue of names of famous people, historical dates, countries, towns, plants, etc., could be prepared. But the selection of a name is a major difficulty for the municipality, since the principal streets need to be given the most prestigious names so the hierarchy of streets has to be matched with the hierarchy of names, an extremely difficult exercise, particularly when streets are given the names of politicians.

2nd Task – Section the town geographically into “units to be addressed”

To make identification and the application of the system easy, the town should be sectioned into “units”, and each unit will contain a certain number of streets. In each project, the evolution of urbanization must be taken into account, so provision must be made for a sizeable increase in the number of streets, in the medium or long term.


3.1 - The case of a small town sectioned into four “units” of 100 streets each

3.2 - The case of a small town undergoing expansion

Streets 200 - 299Streets 100 - 199

Streets 300 - 399

Streets 400 - 499


Streets 300 - 399Streets 400 � 499

extensionarea


1 – The case of a small town (figures 3.1 and 3.2) (fewer than 150 streets)

The town should be divided into three or four zones marked out by the most important streets or by natural limits (rivers, etc.). The different zones selected contain streets numbered in batches of 100 (100 to 199, 200 to 299, etc.). Since the small town has no more than 150 streets when the primary numbering takes place, each zone has about 40 streets and can accept as many again in the future. When a zone has close to 100 streets, the small town enters into the category of medium-sized towns, at which point numbering will be carried out as indicated in the next paragraph.

3.3 - The case of a medium-sized town


3.4 - The case of a medium-sized town sectioned into 4 “units” of 1,000 streets each

200 - 299

100 - 199

300 - 399400 - 499

1.001 - 1.999

2.001 - 2.999

4.001 - 4.9993.001 - 3.999

200 - 299

100 - 199

300 - 399400 - 499

extension area

A.001 - A.999B.001 - B.999

D.001 - D.999C.001 - C.999

1.001 - 1.999

2.001 - 2.999

4.001 - 4.9993.001 - 3.999

extension area


2 – The case of a medium-sized town (from 150 to 1,000 streets) Numbering may be carried out in two different ways: a – Number the town center first (figure 3.3).

• Apply the preceding method when numbering the three or four central zones in batches of 100 numbers.

• As soon as a zone is nearing saturation (100 streets), it is supplemented by a new sectioning into large zones, thus prolonging the first, of 1,000 streets. In this case, each large zone comprises a prefix (number or letter).

- zone 1 = streets 1.001 to 1.999 - zone 2 = streets 2.001 to 2.000 and so on. or, with a letter: - zone A = streets A.001 to A.999 - zone B = streets B.001 to B.999 and so on.

b – Divide the town into three or four zones each containing 1,000 streets (figure 3.4). A 3-figure number should be adopted from the start, to which a prefix (number of letter) will be added as indicated above.


Street addressing the town of Doloba 3.5 - Sectioning into 19 neighborhoods of 500 streets each

Streets ZO.001 - ZO.499

Streets QU.001 - QU.499

Streets ZA.001 - ZA.499

Streets NO.001 - NO.499

Streets EX.001 �- EX.499

Streets GA.001 - GA.499

Streets KO.001 - KO.499

Streets OM.001 -OM.499

Streets MA.001 - MA.499

Streets VA.001 - VA.499

Streets EL.001 - EL.499

Streets RA.001 - RA.499

Streets ZI.001 - ZI.499Streets MI.001 - MI.499

Streets IS.001 - IS.499

Streets BO.001 - BO.499

Streets KI.001 - KI.499

Streets ID.001 - ID.499

Streets NY.001 - NY.499

developed area

municipal border

neighborhood border

neighborhood codification

squatter area


3 – The case of a large town (sample case: Doloba, which has more than 1,000 streets) Two very different scenarios are proposed:

• scenario 1: sectioning into neighborhoods • scenario 2: sectioning into official administrative sectors known as “street

addressing zones”. a – Scenario 1: Sectioning the town into neighborhoods (figure 3.5). This consists of: • sectioning the town by neighborhood as shown in the first task • allocating a number and/or retaining the name of each neighborhood • making allowance for groupings of streets in each neighborhood • the street numbering contains a prefix that may be either a number, or the initials

of the name of the neighborhood, which facilitates identification – for example, KI for the Kibougou neighborhood, which gives streets called KI-001, etc.

Advantages:

- With a relatively small perimeter, the number of streets in each neighborhood is not very high and this limits the amount of confusion. - A small perimeter emphasizes the identity and history of the town and thus makes orientation easier for inhabitants. It seems more familiar to them.

Disadvantages:

- Since the sectors are relatively small, streets often cross several sectors, and this can result in codification difficulties, as the code allocated will differ from one end of the street to the other.


Street addressing the town of Doloba 3.6 - Sectioning of the town into 9 street addressing sectors

streets1.001 - 1.999

streets8.001 - 8.999

streets9.001 - 9.999

streets6.001 - 6.999

streets5.001 - 5.999

streets7.001 - 7.999

streets2.001 - 2.999

streets3.001 - 3.999

streets4.001 - 4.999

developed area

municipal borderzone borderzone number

squatter area

railway


b- Scenario 2: Sectioning the town into official administrative sectors known as “street addressing zones”. This scenario envisages street numbering according to a geographical sectioning of the town.

• Section the town into “street addressing zones”, essentially based on an urban or geographic sectioning (major street, natural boundaries, etc.), which often corresponds with the administrative boundaries.

• Allocate to each sector a tranche of street numbers. Each street number will be preceded by a prefix belonging to the sector in which the street is situated.

• Provision should always be made for future expansion. For example, 250 numbers might be allocated to a sector currently containing 100 streets.

The adoption of the denomination “street addressing zone” instead of the official administrative term means that the numbering system need not be affected should fresh administrative sectioning be undertaken. Advantages:

- Sectioning into street addressing zones makes it possible to have a smaller number of sectors than neighborhoods. Numbering is simpler and easier to remember. - It takes into account administrative sectioning, which facilitates many actions and applications. - The system allows for numbering to be expanded as streets are built, particularly in new neighborhoods.

Disadvantages:

- The zones are extremely large, and there are sometimes very many streets in a neighborhood. Street numbers are often complex (for example, street 1.018), and it can be difficult to preserve strict logic in the numbering. - This system may be simpler for the various administrations, but it is more abstract for inhabitants than a system based on neighborhoods.

3.7 - Major routes and direction of odd- and even-numbered streets


3.8 - Using the shoreline as a reference point for street direction

zone border

Shoreline and reference axis for the direction of street numbering

Direction of even-numbered streets

Direction ofodd-numbered streets

Zone 2

Zone 1 Zone 4

Zone 3

OCEAN

North

Odd-numbered street

Even-numbered street

Streets 100 - 199


Streets 200 - 299 Direction of even-numbered streets

Direction of odd-numbered streets


3rd Task – Determine the orientation of street numbers At this stage, the codification of sectors and streets has been selected and it is time to choose the numerical progression system. To set up the street addressing system:

• We identify linear points of reference (streets, railways, rivers, etc.). We need two axes as close to perpendicular as possible (a north-south axis and an east-west axis), whose intersection is close to the true center of the town. The two axes must match with the limits of street addressing sectors; they most not traverse them.

• One of the axes (for example, north-south) will be the reference point for even-numbered streets, and the other (for example, east-west) for odd-numbered streets.

• The axes define the origin of the street numbers. Street numbers will progress on both sides of each of these axes, from the lowest number to the highest. When you change to another sector, the numbering starts again from zero, but maintains the same order of progression.

As far as possible, axes should be oriented in line with the cardinal directions: north-south and east-west. But this rule can be modified when there are obvious, simple, geographical landmarks, such as a river or perhaps a shoreline. The axis of the river or the shoreline, since it is well known to everyone, can be useful as a location point for the progression of the numbers.


Street addressing the town of Doloba 3.10 - Reference axes and direction of streets

Rue 1

Rue 3

Rue 5

Rue 7

Rue

1

Rue

3

Rue

5

Rue

7

Rue

1

Rue

3

Rue

5

Rue

7

Rue 1

Rue 3

Rue 5

Rue 7

Rue 8

Rue 6

Rue 4

Rue 2 Rue 8

Rue 6

Rue 4

Rue 2

Rue 8Rue 6Rue 4

Rue 2

Rue 2

Rue 4

Rue 6

Rue 8

RuesRuespairespaires




Rues

Rues

impaires

impaires

Eve

Rue

sim

paire

sim

paire

s

Rue

sR

ues

impa

ires

impa

ires

Rues

Rues

impaires

impaires





Rues

Rues

impaires

impaires

Rue

sR

ues

impa

ires

impa

ires

Rue

sR

ues

impa

ires

impa

ires

Rues

Rues

impaires

impaires

0 10,5 1,5 2 km1

municipal bordersector bordernumber of sector

street numbering reference axes direction of street numbering

Rue = street Rues paires = even-numbered streets Rues impaires = odd-numbered streets


The orientation and direction of the sequence of street numbers in Doloba (figure 3.10) The streets are divided into two groups (even and uneven) depending on their orientation, then a direction is chosen for numbering. The topography and the direction of urbanization should be taken into account:

• For streets running north-south, the street numbers will be odd, and the sequence will be done on either side of the railway.

• For streets running east-west, street numbers will be even and the sequence will be done on either side of a major axis (Plénitude Boulevard, separating Sectors 1 and 8).


Street addressing the town of Doloba 3.11 - Numbering of streets by block, in Sector 6 of the town of Doloba

Direction of even-numbered streets

Direction of odd-numbered streets sector borders

block borders

Block 1 6.001 - 6.099

Block 3 6.201 - 6.299

Block 2 6.101 - 6.199

R.6.016

R.6.034

R.6.044

R.6

.007

R.6

.011

BLOCK 1

R.6.016

R.6.116

R.6.120

R.6.140

R.6.108

R.6.034

R.6.044

R.6

.007

R.6

.111

R.6

.121

R.6.116

R.6.120

R.6.140

R.6.108

R.6

.111

R.6

.121

R.6

.011

R.6

.023

BLOCK 1BLOC 1

BLOC BLOC 2 2

R.6.004

R.6.258

R.6.234

R.6.216

R.6.014

R.6.020

R.6

.005

R.6

.233

R.6

.253

R.6

.011

BLOCK 1BLOC 1

BLOC BLOC 2 2

BLOC BLOC 3 3

BLOCK 1BLOC 1

BLOC 2BLOC 2

BLOC 3BLOC 3

BLOCK 4BLOC 4

Principal for numbering streets by sector:

1. The sector is sectioned into blocks bordered by major roads: 2. Block 1 is numbered first :

3. Then Block 2 : 3. Finally, Block 3 :

Sector 6No. 6.001 - 6.999 Sector 6

No. 6.001 - 6.999

Sector 6No. 6.001 - 6.999

Sector 6No. 6.001 - 6.999


Numbering major blocks of land (figure 3.11) When the sector to be addressed is vast and we are faced with the difficulty of organizing an overly large number of streets, streets can be numbered in large blocks separated by arteries, while still maintaining the approach described above. The system adopted makes it possible to supplement numbering as needed when new streets are created, particularly in new neighborhoods. And if one or several of the streets is removed as a result of restructuring, the numbers should be kept in reserve, then allocated as a priority to any new streets in the same sector.

3.12 - Sequential numbering


3.13 - Metric numbering

Metric numbering,before densification

Metric numbering,after densification

8

28

22

52

58

34

17

11

33

45

61

8

28

22

52

58

34

17

11

33

45

61

23

4039

Even Numbers Odd Numbers Even Numbers Odd Numbers

Str

eet 1

.014

Num

berin

g di

rect

ion

Str

eet 1

.014

Num

berin

g di

rect

ion

55

Str

eet 1

.014

2

6

4

10

12

8

3

1

5

7

9

2

6

4

10

12

8

3

3bis

8bis

6bis

8ter

5bis

7bis

1

5

7

9

Sequential numbering,before densification

Sequential numbering,after densification

Even Numbers

Num

berin

g di

rect

ion

Odd Numbers Even Numbers NOdd Numbers

Str

eet 1

.014

Num

berin

g di

rect

ion


4th Task – Select the system for numbering entry[ways 1 – The principal of entryway numbering Numbering may be carried out under two systems: sequential or metric. In either case:

• Odd and even numbers go on opposite sides of the street. • Numbers progress from a point designated as the beginning of the street and

referred to as the “zero point”.

The metric system is strongly recommended for towns that have no pre-existing system. a – Sequential or “classic” numbering (figure 3.12) Existing entryways are numbered one after the other, so the numbering is continuous (2, 4, 6, etc. on the right ride; 1, 3, 5, etc. on the left). This numbering system is the least efficient in the following cases:

• Rapidly progressing urbanization, or restructuring. In this case, an “a”, a “b” or a “c” has to be added whenever buildings are added between two existing – and therefore sequentially numbered – buildings. This makes the numbering very complex and may create confusion.

• Ongoing urbanization. There are generally no limits to the plots of land, and is it difficult to envisage numbering for empty lots.

b – “Metric” or “linear” numbering (figure 3.13) Entryways are numbered corresponding to their distance from the beginning of the street, or the “zero point”. For example, number 5 is situated 5 meters from the beginning of the street, and number 6 is practically opposite number 5. Numbers are therefore not automatically continuous where there are empty lots. To determine what number to allocate,

• Measure the distance between each entryway and the zero point. • This figure is rounded up or down to the closest even or odd figure depending

on the side of the street. For example, the number allocated to the entryway situated 7.5 meters from zero point will be 7 if the building is on the odd-numbered side of the street, and 8 if it is on the even-numbered side.


3.14 - A plaza that is large and/or has a name

The plaza keeps its name and is also allocated a number, derived from the direction the numbering of the streets is taking (even or odd). Numbering on lateral streets is suspended at the plaza, then begins again on the other side. Axial streets stop at the plaza, and a different name is allocated where they continue. 3.15 – A non-codified plaza Since the plaza has no name, no number need be allocated to it. In this case, the buildings located on the plaza will be numbered depending on the numbering of the streets on which they are located. A codified plaza is numbered clockwise froma zero point.

3.16 - The principle for numbering a codified plaza

Street 2.126Place des Antilles 2.128

Street 2.12 Street 2.124

Street 2.122


Street 2.134

Stre

et 2

.017

Stre

et 2

.015

Stre

et 2

.013

Stre

et 2

.011

Street 2.130

area where squaresare numbered


Street 2.124

Street 2.122

Street 2.132

Str

eet 2

.017

Stre

et 2

.015

Stre

et 2

.013

Str

eet 2

.011

Street 2.130

ZERO

15 M

No. 15

No. 31

No. 49

No. 67

No. 81

No. 99

STRE

ET 5

.039

STREET 5.037

STREET 5.043 STREE

T 5.

041

STREET 5.042 STREET 5.046STREET 5.044

No. 31

No. 85

"zero"

No. 61

No. 11

11 m

square3.028

street3.030

street3.026

stre

et3.

035

stre

et3.

033


The metric system has several advantages: • Numbering is final, so there is no need for a’s, b’s or c’s; • It is suitable for the rapid development of neighborhoods, and for

restructuring. When a new building is erected the number is determined immediately, simply by measuring the distance from the zero point.

• It makes it easier to locate addresses when, for example, the number 109 is always opposite the number 110, and 109 meters from the beginning of the street.

• Therefore, it simplifies the task of the different administrations (simplified routes for mail delivery, water meter reading, electricity meter reading, telephone services, etc.).

• It provides some useful data – the linearity of roadways as well as their surface area.

• It simplifies the addition or removal of entryway numbers. Addition: each new building corresponds to a unique number since it is the relevant distance from the zero point. Removal: a regrouping of lots may result in the outright removal of certain numbers, without this creating any confusion.

2 – Codifying plazas and intersections Several cases may be present: a – a plaza bordered by four lateral streets: Two options (see 3.14 and 3.15):

- The plaza is given a code: if, for example, it already has a name, or if it is a large plaza. All entryways opening onto the plaza will have a specific codification. Numbering on streets bordering the plaza will be suspended at the plaza, and then continue after the plaza. Numbering of entryways on the plaza will begin from a zero point, determined arbitrarily, and continue on around the plaza. The address will look something like this: No.38, Plaza 2.138.

- The plaza is not coded: The numbering of the buildings opening onto the plaza will depend on the numbering of the streets on which they are situated (3.14).

b – a plaza whose center is the virtual intersection point of the streets, and which has no tangential street: (3.15) The plaza will have both a name and a number. For example, 3.026 Street opens onto Plaza 3.026, and is extended by 3.030 Street. Numbering is done from the zero point, circling the plaza (3.16).


Impasse 2015.125

Impasse 2015.76

76 meters frombeginning of street

125 meters frombeginning of street

Even Numbers Odd Numbers

7

49

23

31

42 56

28

3.17 - numbering of dead-end streets

3.18 - Codification of a street with a name and which crosses through several sectors

Rue 3

3322

11

11 sector number

doorway number

sector border

21

6

26

70

1

11

77

43Street 1.060


beginning and end of street

Avenue du D�veloppement Planifi�

In this case, the street does not keepthe same number, since this wouldresult in inconsistency between thenumbering of the various sectors. Butit does keep the same name, andentryway numbering is contnuousfrom one end of the street to the other, even the street crossesinto another sector and changes code.


3 – Codifying dead-end streets Streets less than 100 meters long and with only one exit point are considered as dead-end streets. The dead-end street carries a code analogous to a street code. The numbering of dead-end streets is identical to that for ordinary streets. The dead-end street is given the number of the street it comes out onto, followed by a suffix (letter or number) determined by the codification method adopted.

Questions What can be done when a street crosses several sectors? (3.18) If a street crosses two adjoining sectors, i.e., sectors not separated by a major dividing line (a railway, a major heavily-traveled avenue, a river, etc.), similar numbering should be adopted. Such continuity will facilitate identification. For example, between Sector 1 and Sector 2, a street will be numbered 1.22 in Sector 1 and 2.22 in Sector 2. However, this should not be treated as a hard-and-fast rule, since its strict application could result in disorder and inconsistency in the logical progression of each sector. For a street that bears a name, however, an effort will be made to number buildings from one end of the street to the other, i.e., not to start again from zero on changing sector. This will be done even if the number of the street changes from one sector to another. What can be done when a non-addressable zone is situated in the middle of a neighborhood to be addressed? (3.19) When a non-addressable zone is situated in the heart of a zone to be addressed, as is the case for Sector 9 in Doloba, for example, we recommend giving the major streets in the unstructured zone a code, while keeping the general direction of progression. A series of numbers will be set aside for allocating once the neighborhood has been rehabilitated and structured. It is also possible to allocate a code to blocks of houses by linking them to a street, for example block 9204/1. What should be done with the old identification system?

- keep it as is and address the rest of the town, using a new system - discard it and address the entire town with the new system


3.19 - Street addressing the major streets in an unstructured neighborhood

Street 9224

Street 9204

9204/1

Street 9202

Street 9206

Street 9208

Street 9

244

Street 9

246

Street 92239223/4

9223/2

Street 9243

Street 9245

Street 9233

Street 9203

Street 9205

Area with structured housing

Squatter area


Large towns will often have a partial street addressing system already in place, covering the town center. Should this system be integrated with the new street addressing system, and if so, in what way? One option that is often used is to keep the names, but make adjustments in order to facilitate identification:

• Streets that already have names will keep them, but in addition they will be allocated numbers linked to a geographical dividing line, to facilitate identification.

• In order to differentiate streets bearing identical numbers (recent land developments), they will be given a prefix indicating the number of the “unit” in which they are situated. If there are several identical numbers within the same neighborhood, the number of the street will be given followed by a letter (for example, Street 1.14A, Street 1.14B, etc.).

• Streets with no name will be allocated a number in accordance with a geographical sectioning.

selecting the codification system -...

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