Dataset and Section Crossing

Definitions

Dataset Section

A dataset is broken down into sections for easier data processing. Sections are based on Administrative Areas. In most countries, sections are Order 8 Administrative Areas, but there are some countries that are sectioned by Order 9 Administrative Areas (e.g., U.S., China).

Note: "Sections" are not available in Shapefile or OSL. Conversion records only exist in those formats between Datasets.

Relationships

Relationships were defined earlier in this user guide.

See Relationships.

See also Features in Section Crossing Relationships later in this user guide for examples.

Note: No conversion records are made for "foreign" features in a relationship.

Conversion Records

For features that are section-crossing (GDF-AS) or technical dataset-crossing (GDF-AR, Shapefile), conversion records are created to provide a relation between the local and the foreign feature ID.

Conversion records are delivered as either separate records (GDF-AS: record 46) or as separate files (GDF-AR: CN1-CN4; Shapefile: CN) to enable dataset crossing linking of Features. They contain the ID of a feature in the current dataset together with the ID of the same feature in the neighboring dataset.

The dataset identifier of the foreign dataset differs from the internal dataset identifier when adjacent sections belong to different countries.

Example: Internal dataset is Spain (country code 724) and the foreign dataset is Portugal (country code 620) then the dataset IDs in each dataset differs.

Example: For technical datasets that belong to one country, the dataset IDs are the same.

The section identifiers of the foreign dataset always differ from the section identifier of the internal dataset.

The following are the features that the conversion records can be made for:

POINT	LINE	AREA	COMPLEX
Administrative Boundary Junction
Brunnel
Center Point of Feature
City Center
Junction
Railway Element Junction
Water Center Line Junction
	Adress Area Boundary Element
	Brunnel
	Ferry Connection
	Railway Element
	Road Element
	Water Center Line
	Water Element
		Index Area
		Urban Agglomeration
			Intersection
			Road
			TMC Location
			TMC Path

Features with a split indicator of "0" (when lying on a section border) or "1" will automatically generate conversion records.

IMPORTANT:

All parts of a feature that reside in a number of sections (adjacent and not adjacent) are linked via conversion records by chaining the IDs of sections, from lowest to highest.

Figure: Chaining Section IDs

Split Indicators (GDF Format Only)

A "Split Indicator" is a coded value indicating if all composing parts of a feature are present within a section or if some parts are missing. Split indicator values are found in:

GDF line records (GDF-AS record 52; GDF-AR .LIN file);
GDF area records (GDF-AS record 53; GDF-AR .ARE file); and
GDF complex feature records (GDF-AS record 54; GDF-AR .CMP file).
Split indicator values are:

0 = A line, area or complex feature represents the entire feature.
1 = A line, area or complex feature is split. When split indicator = 1, conversion records are always present for:
- lines - toward adjacent components only;
- areas - toward components in all involved sections;
- complex features - toward components in all adjacent sections.
2 = The feature is split but no conversion records are necessary. The feature has the same feature ID in each section within the same dataset.

MultiNet Objects / Features and Dataset Section Crossing

Not all MultiNet^® Level 0, Level 1 and Level 2 objects are dataset or section crossing. See the table below.

OBJECTS / (LEVEL)	CAN BE SECTION CROSSING	CAN LAY ON A SECTION BORDER	CONVERSION RECORDS	SPLIT INDICATOR / (VALUES)	NOTES
Nodes / (0)	No	Yes	No	No
Edges / (0)	No	Yes	No	No
Faces / (0)	No	No	No	No
Point / (1)	No	Yes*	Yes	No	Conversion records are generated when a point feature lies on a section border.
Line / (1)	Yes	Yes*	Yes**	Yes / (0,1)	A road element that lies completely on the section border has a split indicator of "0." The road element is described in both sections.
Area / (1)	Yes	No	Yes	Yes / (0,1)
Complex Features / (2)	Yes	Yes*	Yes	Yes / (0,1)

* Features with split indicator = "0" that lie on a section border will generate conversion records.

** Conversion records are only created for line features that lay on a section or dataset border.

Conversion Record Examples

Point Feature on a Section Border

Figure: Point Feature on a Section Border

GDF-AS (Section 3, record 46)

46 56 305 11901202411 11901202411

Explanation: In the GDF-AS conversion record (46), the internal section is Section 3, which is identified in the Section Identification Subrecord (1601) and not shown here. The foreign section is 305, and the feature ID in both section 3 and section 305 is 1901202411.

GDF-AR (CN1)

56 31901202411 1 56 3051901202411

Explanation: In the GDF-AR conversion record (CN1), the internal section is Section 3 (shown). The foreign section is 305, and the feature ID in both section 3 and section 305 is 1901202411.

Note:

Conversion Record: A point feature only generates a conversion record when it lies on a section border.
Split Indicator: There is never a split indicator for a point feature.
In Shapefile format, Junction IDs on dataset borders have a "10000" prefix. See also Working with Junctions on Dataset Boundaries in Shapefile earlier in this user guide.

Line Feature on a Section Border

Figure: Line Feature on a Section Border

GDF-AS (Section 110000117, record 46)

46 9840 110000128 2 900057420 2 900057420 0

Explanation:

In the GDF-AS conversion record (46), the internal section is Section 110000117, which is identified in the Section Identification Subrecord (1601) and not shown here. The foreign section is 110000128, and the feature ID in both section 110000117 and section 110000128 is 900057420.

Area Feature on a Section Border

Area features on a section border are represented similarly to line and point features as described above:

the internal section identifier is in record 1601;
the foreign section identifier is in record 46; and
the foreign feature and the internal feature IDs are identical and are also found in record 46.

Complex Features Crossing a Section or Dataset Border

Complex features have either split indicator "0" or "1."

Conversion records and split indicators differ when complex features cross sections within the same technical dataset compared to when they cross different datasets.

In the figures below, an intersection is represented by the brown lines for road elements and the white dots for junctions. The road elements that intersect are represented by the orange lines.

Figure: Complex Features Crossing Sections in the Same Technical Dataset

Explanation:

In Figure 1 above, the complex feature has split indicator = "1" in both sections A and B. The components of the intersection do not lie completely in one section. Conversion records are generated.

In Figure 2 above, the complex feature has split indicator = "0" for Section A. All components of the intersection lie completely in the section.

In Section B, the complex feature has split indicator = "1." Only the components of the intersection that lie on the border lie in Section B. Conversion records are only generated for Section B.

Conversion record dataset identifiers are identical for both sections.

Figure: Complex Features Crossing Sections in Different Technical Datasets

Explanation:

In Figure 1 of the above example, the complex feature has split indicator = "1" in both sections A and B. The components of the intersection do not lie completely in one section. Conversion records are generated.

In Figure 2 of the above example, the complex feature lies completely in Section A but it has Split Indicator = "1" instead of "0." This is because the feature lies on a technical data set border and there is no information if the feature has parts in the other technical dataset. The split indicator here only shows the possibility of components in the other technical data set.

As in the first example, the feature in Section B has Split Indicator = "1."

Conversion records are generated for both features in both sections of the different technical datasets. Conversion record dataset identifiers are different for both sections.

Features in Section Crossing Relationships

All features that are part of the relationship and that lie on a section border or that cross a section border are defined in each involved section and have conversion records. A relationship is stored in the section or sections where the relationship has all parts or most of its parts.

The Relationship is defined in the minimal possible number of sections where all relationship parts occur.
Relationships are not repeated for those relationship parts on the section border (those that are part of a conversion record) when the feature is already part of the relationship in the other section.
Feature in Area Relationships information is not stored in GDF files for a foreign section area.

In the TomTom product compilation process, features on section borders can contain different information. See example below.

Figure: Example of Road Element in Named Area Relationship on Section Border

In the example above, if GDF File #2 is compiled before GDF File #1, the right side of the road element on the section border has a relationship with Farmington Hill located in GDF File #2, but no relationship with the left side of the road element with Section A.

From Section A point of view, the right side of the road element on the section border belongs to the foreign section (Section B) and therefore GDF File #1 does not store a relationship on either side of the road element.

The section where the relationship is stored will have its parts identified by that section identifier as much as possible.
The relationship always has to be defined in the section that has the main relevant part.
Relationships involving Lines occur once per Line side.

In GDF-AS format relationship record 50 and conversion record, the FEAT_CAT field holds the feature definition type. Below are the codes available:

Table 1.
FEATURE CATEGORY	FEATURE CATEGORY CODE
Point	1
Line	2
Area	3
Complex	4

In GDF-AR format, relationship record *.RLP identifies the feature type in the FeatCat field.

Attributes of Features on Section Borders

Sections at the Internal Dataset Border, Same Country

When different countries are part of the same TomTom internal dataset, the rules below are valid:

Point Features

Point features are defined in each section. The identifiers of the Point features are not identical and conversion records are defined between both point features. Attributes are not guaranteed to be populated on both sides. Merging of the attributes, followed by deduplication is required when Point features are dissolved into one.

Line Features

Line features are defined in each section. The identifiers of the Line features are not identical and conversion records are defined between both line features. Attributes are not guaranteed to be populated on both sides. Merging of the attributes, followed by deduplication is required when Line features are dissolved into one.

Area Features

Area feature parts are defined in each section. The identifiers of the area features are not identical and conversion records are defined between both area feature parts. Attributes are not guaranteed to be populated on both sides. Merging of the attributes, followed by deduplication is required when area features are combined into one.

List of Relationships

On the following pages, examples of relationships that can cross section borders are explained.

Table 2.
CODE	NAME
1001	Road Element in Order 8 Area
1003	Road Element in Named Area
1006*	Service in Order 8 Area
1007	Built-up Area in Order 8 Area
1008	Ferry Connection in Order 8 Area
1010	Enclosed Traffic Area in Order 8 Area
1011	Road Element in Built-up Area
1013	Ferry Connection in Named Area
1014*	Service in Named Area
1016*	Service in Built-up Area
1022*	Service Along Road Element
1026*	Service Belonging to Service
1029*	Centre Point of Feature Belonging to Feature
1039	Reference Point Along Road Element
1070	Address Area Boundary Element in Built-up Area
1071	Address Area Boundary Element in Named Area
1072	Address Area Boundary Element in Order 8 Area
1073	Address Area Boundary Element in Order 9 Area
2101	Calculated Prohibited Maneuver
2102	Restricted Maneuver
2103	Implicit Turn
2103	Prohibited Maneuver
2104	Priority Maneuver
2128	Signpost Information
2199	Image Maneuver
2200	Grade Separated Crossing
2300	Traffic Sign along Road Element
2400	Place Within Place
9001*	Vicinity: Service - City Center
9201	Address Area in Named Area
9202	Enclosed Traffic Area in Named Area
9203	Built-Up Area in Named Area
9204	Area Replaced by Index Area
9401	Bifurcation
9501	Road Element in Order 9 Area
9502*	Service in Order 9 Area
9503	Order 9 Area in Order 8 Area
9504	Enclosed Traffic Area in Order 9 Area
9856*	Ferry Termial Along Ferry Connection
9860	Lane Connectivity

* Relationships with MultiNet and MultiNet POI product

Quick Links to Relationship Types:

Point Feature, Point Feature Relationships

Point Feature, Line Feature Relationships

Point Feature, Area or Complex Feature Relationships

Line Feature, Area Feature Relationships

Area Feature, Area Feature Relationships

Maneuvers and Maneuver-like Relationships

Relationship Examples

Point Feature, Point Feature Relationships

Relationships

Table 3.
RELATIONSHIP CODE	RELATIONSHIP
1024	Service at Junction
1026	Service Belonging to Service
9001	Vicinity: Service - City Center

Table 4. Examples of Point Feature, Point Feature Relationships.
	The mininimum number of Sections where all relationship parts occur is 1. This is Section A. There is no relationship for the Point features in Section B as their corresponding point features (both stored in conversion records) are already part of the relationship. Result: Relationship is stored in Section A only.
	The minimum number of Sections where the relationship parts occur is 2. This is Sections A and B. Result: Relationship is stored in Section A and Section B.
	The mininimum number of Sections where all relationship parts occur is 1. This is Section C. There is no relationship for the Point features in Section A, B and D as their corresponding point features (stored in conversion records) is already part of the relationship. Result: Relationship is stored in Section C only.
	The minimum number of Sections where the relationship parts occur is 2. This is Section C and B. Result: Relationship is stored in Section C and Section B.
	The minimum of Sections where the relationship parts occur is 2. This is Sections A or C and Sections B or D. Result: Relationship is stored in Sections A and Section B (one of the possibilities is maintained).

Point Feature, Line Feature Relationships

Relationships

CODE	RELATIONSHIP
1022	Service along Road Element
2300	Traffic Sign along Road Element
9856	Ferry Terminal along Ferry Connection

Note: Relationships involving Road Elements occur once per Road Element side.

Table 5. Examples of Point Feature, Line Feature Relationships
	The mininimum number of Sections where all relationship parts occur is 1. This is Section A. There is no relationship for the Point or Line feature in Section B as their corresponding point or line features (both stored in conversion records) are already part of the relationship. Result: Relationship is stored in Section A only.
	The minimum number of Sections where the relationship parts occur is 2. This is Sections A and B. Result: Relationship is stored in Section A and Section B.
	The mininimum number of Sections where all relationship parts occur is 1. This is Section C. There is no relationship for the Point features in Section A, B and D as their corresponding point features (stored in conversion records) is already part of the relationship. Result: Relationship is stored in Section C only.
	The minimum number of Sections where the relationship parts occur is 2. This is Sections C and B. Result: Relationship is stored in Section C and Section B.
	The minimum of Sections where the relationship parts occur is 2. This is Sections A or C and sections B or D. Result: Relationship is stored in Section A and Section B. (one of the possibilities is maintained).

Point Feature, Area or Complex Feature Relationships

Relationships

CODE	RELATIONSHIP
1006	Service in Order 8 Area
1014	Service in Named Area
1016	Service in Built-up Area
1029	Center Point of Feature belonging to Feature
9502	Service in Order 9 Area

Table 6. Examples of Point Feature, Area and Complex Feature Relationships
	The mininimum number of Sections where all relationship parts occur is 1. This is Section A. There is no relationship for the Area feature in Section B as its corresponding area part (both stored in conversion records) are already part of the relationship. Result: Relationship is stored in Section A only.
	The minimum number of Sections where the relationship parts occur is 2. This is Sections A and B. Result: Relationship is stored in Section A and Section B.
	The mininimum number of Sections where all relationship parts occur is 1. This is Section C. There is no relationship for the area features in Section A, B and D as their corresponding area parts (stored in conversion records) is already part of the relationship. Result: Relationship is stored in Section C only.
	The minimum number of Sections where the relationship parts occur is 1. This is Section C. There is no relationship is Section A as the corresponding Point feature is already part of a relationship in Section C. Result: Relationship is stored in Section C.

Deviation to the Point in Area Relationship

Figure: Deviation to the Point in Area Relationship

In a specific section crossing area which is one object Z (conversion records are defined between Z in section A and Z in section B), a point element on the section border may have a relationships to an area feature that does not contain the point feature.

In the above situation object area Z has a part in section A and a part in section B. Applying rules of storing the relationships in a minimal set of sections, the relationships would only occur in section B for Point Feature in Area relationships. Because the area feature also has a sub part in section A, the point element is related to sub part Z in A and the relationship is defined in section A, even though the point element is not contained in sub part Z in section A.

Line Feature, Area Feature Relationships

Relationships:

CODE	RELATIONSHIP
1001	Road Element in Order 8 Area
1003	Road Element in Named Area
1008	Ferry Connection in Order 8 Area
1011	Road Element in Built-up Area
1013	Ferry Connection in Named Area
9501	Road Element in Order 9 Area

Note: Relationships involving Road Elements occur once per Road Element side.

Table 7. Examples of Line Feature, Area Feature Relationships
	The minimum number of Sections where the relationship parts occur is 2. This is Sections A and B. Result: Relationship is stored in Section A and Section B.
	The minimum number of Sections where the relationship parts occur is 1. This is Section B. Result: Relationship is stored in Section B.
	The minimum number of Sections where the relationship parts occur is 2. This is Sections C and D. Result: Relationship is stored in Section C and Section D.
	The minimum number of Sections where the relationship parts occur is 2. This is Sections A and C. Result: Relationship is stored in Section A and Section C.

Figure: Two Different Area Objects at the Section Border

Compliant to the rule "The Relationship is defined in the minimal possible number of sections where all relationship parts occur", Line Feature in Area Feature Z is only defined in section A, not in B. Line Feature in Area Feature Y is only defined in section B, not in A.

Deviation to the Line Area Relationship

Figure: Deviation to the Line Area Relationship

In a specific section crossing area which is one object Z (conversion records defined between Z in A and Z in B), a line element that has the area adjacent to one side may have a relationships to an area feature that is not adjacent to that line.

In the above situation object area Z has a part in section A and a part in section B. Applying above rules of storing the relationships in a minimal set of sections, the relationships would only occur in section B with side of line Right for Element in Area relationships. Because the area feature also has a sub part in section A, the line element is related to sub part Z in A and the relationship is defined in section A with side of line for the Right side, even though the line element is not adjacent to sub part Z in section A for its left or right side.

Area Feature, Area Feature Relationships

Relationships:

CODE	RELATIONSHIP
1007	Built-Up Area in Order 8 Area
1010	Enclosed Traffic Area in Order 8 Area
1071	Address Area in Named Area
2400	Place within Place
9202	Enclosed Traffic Area in Named Area
9203	Built-Up Area in Named Area
9204	Area Replaced by Index Area
9503	Order 9 Area in Order 8 Area
9504	Enclosed Traffic Area in Order 9 Area

Table 8. Examples of Area Feature, Area Feature Relationships
	The minimum number of Sections where the relationship parts occur is 1. This is Section A. Result: Relationship is stored in Section A only.
	The minimum number of Sections where the relationship parts occur is 2. This is Sections A and B. Result: Relationship is stored in Section A and Section B.
	The minimum number of Sections where the relationship parts occur is 1. This is Section C. Result: Relationship is stored in Section C.
	The minimum number of Sections where the relationship parts occur is 4. This is Sections A,B, C and D. Result: Relationship is stored in Sections A, B, C and D.

Maneuvers and Maneuver-like Relationships

Relationships:

CODE	RELATIONSHIP
2101	Calculated Prohibited Maneuver
2102	Restricted Maneuver
2103	Prohibited Maneuver
2103	Implicit Turn
2104	Priority Maneuver
2199	Image Maneuver
9401	Bifurcation
9860	Lane Connectivity

Note: RE = Road Element; JC = Junction

Note: Relationships involving Road Elements occur once per Road Element side.

Table 9. Examples of Maneuvers and Maneuver-like Relationships
	The minimum number of Sections where all relationship parts occur is 1. This is Section A. Result: Relationship is stored in Section A. Section A: RE a(A) JC(A) RE b(A)
	The minimum number of Sections where all relationship parts occur is 1. This is Section A. Result: Relationship is stored in Section A. Section A: RE a(A) JC(A) RE b(A)
	Bifurcation: The mininum number of sections where all relationship parts occur is 2. This is Sections B and C. Section B: RE a(B) JC(B) RE b(C) RE c(C) Section C: RE a(B) JC(C) RE b(C) RE c(C)
	The minimum number of Sections where all relationship parts occur is 1. This is Section D. Result: Relationship is stored in Section D. Section D: RE a(D) JC(D) RE b(D)
	The minimum number of Sections where all relationship parts occur is 2. This is Sections A and C or B and D. Result: Relationship is stored in Sections A and C. Section A: RE a(C) JC(A) RE b(A) Section C: RE a(C) JC(C) RE b(A)