How to Use MultiNet Shapefile and OSL
Parent topic: How to Use MultiNet Shapefile and OSL

Geocoding with MultiNet® Shapefile

The MultiNet® Shapefile Geocode Layer (gc table) contains all address information necessary for geocoding on different levels, from house number to country level, by containing Administrative Name Attributes or by referring to a Feature Identifier in another table.

The most extensive address information content is located at the street level. The gc table has its own geometry objects, which are the extracted roads and address areas from the Network layer (nw table).

On higher levels, address information is present as an Attribute and also by referring to themes such as Postal Districts, Other Named Areas, Built-up Areas, Centers of Settlement and Administrative Areas. A direct reference to a Street and a higher-level Administrative Area of any type is thereby made.
Note: All name information needed to geocode to an address is contained as an attribute in the Geocode Layer (gc). See table below.
gc ATTRIBUTE ATTRIBUTE DESCRIPTION
NAMEPREFIX Prefix portion of the FULLNAME, often the street type (e.g., Carettera, Rue)
NAMESUFFIX Suffix portion of the FULLNAME, often the street type (e.g., Street, Ave, Blvd)
PREDIR Prefix Directional field for North(N), South (S), East (E), West (W)
FULLNAME Full Street Name
NAME The main body portion of the full street name (e.g., "Sirai" component of "Strada Statale Sirai")
SUFDIR Suffix Directional field for North(N), South (S), East (E), West (W)
L_APNAME Administrative Place Name (City) on Left side of Street
R_APNAME Administrative Place Name (City) on Right side of Street
L_PC Postal Code Left
R_PC Postal Code Right
L_AXON Administrative Area Left
R_AXON Administrative Area Right
L_F_ADD (Optional) Left from address number
L_T_ADD (Optional) Left to address number
R_F_ADD (Optional) Right from address number
R_T_ADD (Optional) Right to address number

House Number and Street Level Geocoding

The TomTom® road network is represented by three different network levels: STNW, ICNW and MRNW. See Road Networks earlier in this user guide for more details. The MRNW network is not suitable for good geocoding results.

A House Number is attached to an Addressable Element in the following ways:

1. At the side of a Road Element between two intersections that has the same Street Name, Postal Code and Place Name. See figure below.

Figure: House Numbers on Addressable Element

In the above graphic, A1 is an Addressable Element because it forms a unit that runs from the left-most Intersection to the Intersection of S1 with S2. That Addressable Element unit has street name S1. Street name S2 also applies to A2, A3 and A4: they belong to Street Name S1. Addressable Elements A5, A6, A7 and A8 belong to S2.
2. At the side of the Boundary of an Address Area that is not intersected by other roads and that has the same Street Name, Postal Code and Place Name. See figure below.

Figure: Address Area

In the above graphic, A1 forms a continuous part of the Address Area, going from the west road to the north road. Here, the House Number Information is stored only at one side (the outside) of the Address Area Boundary Element.

House Number Ranges

House number information in the TomTom® mother database is stored as a range (see graphic of address range interpolation above). A House Number Range is a set of house numbers related to each side and the extremities of a particular Addressable Element. Addressable Elements correspond in most cases to Transportation Elements in MultiNet® Shapefile.

In most cases, the representation of the first and last house number, together with the left and right house number structure (L_STRUCT and R_STRUCT in the gc table) associated with the Addressable Element, is sufficient to locate an address.
Note: Because of the non-linearity of some street addressing, the lowest or highest house number of an Addressable Element does not necessarily make it the first or last house number of that Addressable Element. Intermediate house numbers are sometimes needed to clearly assign an address to an Addressable Element. Intermediate numbers are stored in the ih (Intermediate House Numbers) table. In the gc table, those house number ranges having Intermediate House Numbers are flagged in the R_INTM field.
Below are some examples of addressing schemes and how they are handled in MultiNet® Shapefile.

Figure: Addressable Elements and House Numbers

The table below describes the house numbers in the above drawing and how they are represented in the gc table.
ADDRESSABLE ELEMENT HOUSE NUMBER STRUCTURE ATTRIBUTE CODE IN gc TABLE R_STRUCT OR L_STRUCT NOTES
A1 Even 2 Only one even house number.
A2 No house number 1 A2 Road Element has no house numbers at all.
A3 Even 2 Only even house numbers in ascending or descending order.
A4 Odd 3 Only odd house numbers in ascending or descending order.
A5 Mixed 4 Even and odd house numbers in ascending or descending order.
A6 Irregular 5 Even and/or odd house numbers in no particular order.

Address Information: Special Cases

Addresses with Apartment Blocks

Figure: Addresses with Apartment Block

  • In the figure above, Apartment block BldgA has one entrance and has only one house number assigned. In this case, the house number is assigned to addressable element A9.
  • Apartment block BldgB also has only one entrance, but all house numbers residing in this apartment block are even numbers 2 to 100. All of these house numbers are assigned to addressable element A17, since A17 contains even numbers for the street.
  • Apartment block BldgC also has only even house numbers. This block, however, has two entrances. The first entrance is located at addressable element A18. In the gc table, if this entrance gives access to house numbers 2 to 34, those numbers are stored in the address attributes to the right side of the street. This street's left house numbers (assigned to addressable element A20) are irregularly structured.
Note: If an apartment building has house numbers, but the addressable element in the gc layer's R_STRUCT or L_STRUCT value is 0 (no structure), addresses is not assigned to the Road Element.

Streets with Two Street Names

If a street has two street names, but only one official street name and one alternate street name, the full house number range is assigned to both the official street name and alternate street name. The street names are applicable to both sides of the streets.

If a street has two official street names and each of the street names belongs to only one side of the street, and thus to only one Addressable Element, the record for the Transportation Element is repeated, one time for each "Side of Line (SOL)," which for the first record is set "1 (Left)," and for the second "2 (Right)."

Dead-End Streets

On a dead-end street, house numbers may not be well ordered, especially at the end of the street. House numbers are allocated to the most appropriate Addressable Element.

Alpha-Numeric House Numbers

If a house number is alpha-numeric (e.g., 4a) this number appears as "4" in the gc table's left or right first house number attribute field (L_F_ADD or R_F_ADD). This house number is called the "Base House Number." The complete information "4b" is stored in a separate Left (or Right) First Full House Number field (L_F_F_ADD or R_F_F_ADD).

Address IDs and Official Street Codes

The gc table fields L_ADDRID and R_ADDRID store stable, definitive TomTom® IDs that are used for joining information with a Transportation Element or a group of Transportation Elements belonging to the same street (a unit with the same Street Name). When a match is made between an Address ID and a geocoded Feature, the match can be translated into a Relation of the Feature with the Transportation Element or the street it belongs to. Official Street Codes are used by authorities in some countries for identifying a street. Official Street Codes are stored in the sc (Official Street Codes) table.

Geocoding on Lower Levels of Accuracy

The gc layer also allows for geocoding on lower levels of accuracy.
Note: The gc layer contains numerous attributes referring to Built-up Areas, Postal Districts and Administrative Area levels. These references are stored in the Transportation Element Belonging to Area (ta) table in the field ARETYP.
Note: It is not necessary to use the gc table for geocoding on other levels. Using the gc table limits the amount of matches to roads that are included in the gc table (Named Roads). Using the nw table enables geocoding on other levels of all roads.

Administrative Area Information

Information on the lowest Administrative Order at both sides of the Road Element appears in the the following fields: L_LAXORD and R_LAXORD (left and right Lowest Administrative Area Order); L_LAXONLC and R_LAXONLC (left and right Lowest Administrative Area Official Name Language Code); L_LAXON and R_LAXON (left and right Lowest Administrative Area Official Name).

The second-lowest Administrative Area information is included in the Attributes L_AXON and R_AXON (left and right second-lowest Area Official Name).

For the European database, the Administrative Area Codes of Administrative Order 0 and 8 levels are present as L_ORDER00, R_ORDER00, L_ORDER08 and R_ORDER08.
Note: The gc tables in the U.S. MultiNet® Shapefile product store the Administrative Area Codes of Administrative Orders 0 (Country) and 1 (State) in the fields L_ORDER00, R_ORDER00, L_ORDER01 and R_ORDER01.

The relationship for all Road Elements-named and unnamed-and the Administrative Area in which they are located is stored in the Transportation Element Belonging to Area (ta) table.

Built-Up Area Information

The Road Element that a Built-up Area belongs to is represented in the Transportation Element Belonging to Area (ta) table. The ARETYP attribute has the value 3110.

Postal Code Information

Postal Districts are areas that are defined as units for postal services. These areas are defined by national postal organizations. Postal Districts are referred to in the GC table in the Postal Codes L_PC and R_PC (left and right Postal Code) fields.

Postal Codes apply to a certain area. In the U.S., for example, this area is a block. For the U.S., the ZIP+4 Code is an extension to the Postal Code ZIP Code and provides additional street-level postal information. It is captured in the Attributes L_PCEXT and R_PCEXT (left and right Postal Code [ZIP+4]) fields.

Administrative Places Information

An Administrative Place corresponds to a non-hierarchical Administrative unit. These units cannot be categorized in the Administrative Order levels (0-9). They are referred to in the Transportation Element Belonging to Area (TA) table by the ARETYP codes 1165 to 1199. For Road Elements on the Administrative Place boundary, the Side of Line is stored in the attribute SOL.

Geocoding on Other Levels

Other Named Areas (for example, Census Districts or Index Areas) are not categorized as Administrative Areas or Administrative Places. Still, it is possible to perform a geocoding operation on these areas, which are captured in the Other Named Areas (oa) layers. The link to the Street Network can be established through the Transportation Element Belonging to Area (ta) table.

Parent topic: How to Use MultiNet Shapefile and OSL