Dictionary, Census of Population, 2016
BlockfaceDictionary, Census of Population, 2016
Blockface

Definition

A blockface represents one side of a street between two consecutive features intersecting that street. The features can be other streets or boundaries of standard geographic areas. Blockfaces are used for generating blockface representative points, which in turn are used for geocoding and census data extraction when the street and address information are available.

Reported in

2016, 2011, 2006, 2001, 1996, 1991, 1986, 1981, 1976, 1971

Remarks

Population and dwelling counts are not disseminated for individual blockfaces, since there are confidentiality concerns about releasing small population and dwelling counts at this level of geography.

Table 1.1 shows the number of blockfaces by province and territory.

Refer to related definitions of geocoding; representative point and Spatial Data Infrastructure (SDI).

Changes prior to the current census

Minor changes in 2011:

• With the redesign of the road network model for 2011, the blockface became a segment-level attribute with a unique identifier for each side on all road segments from which blockface representative points are generated.

Minor changes in 2006:

• The concept of enumeration area (EA) was replaced by collection blocks (COLB) for 2006. The EA sub-block trapezoid polygons were also removed at this time.
• Blockfaces were no longer formed at NTS map tile limits as in 2001 since roads were modified cross map tiles without segmentation.

Major changes in 2001:

• Blockfaces were defined for the entire country, rather than only in urban centres covered by the former street network files.
• Blockfaces were formed by addressable and non-addressable streets, rather than by addressable streets only.
• Two blockfaces were generated opposite a road T-junction, rather than just one blockface.
• Blockfaces were not formed when physical features (such as rivers or railroads) intersected the road, unless these features were coincident with a boundary of a standard geographic area.
• Blockfaces were not formed when a single-address enumeration area (EA) was smaller than a city block. In these cases, known as an EA sub-block, the polygon was offset from the street and digitally represented as a standardized trapezoid, rather than represented as a polygon intersecting the street.
• Blockfaces were formed when streets crossed the limits of map tiles. (The map tiles, which were based on the National Topographic System of Natural Resources Canada, formed the Canada-wide coverage in the 2001 National Geographic Base.)
• Population and dwelling counts were not disseminated for individual blockfaces.

Prior to 2001:

• Blockfaces were defined only in urban centres covered by street network files.
• Blockfaces were formed by addressable streets only.
• Only one blockface was generated opposite a road T-junction.
• Blockfaces were formed when physical features intersected roads, even when the boundaries of standard geographic areas were not coincident with these features.
• Blockfaces were formed when a single-address EA was smaller than a city block since the EA was digitally represented as a polygon intersecting the street.
• Blockfaces were not formed when streets crossed the limits of map tiles, since map tiles were not used.
• Population and dwelling counts were disseminated for individual blockfaces.

Prior to 1991, blockfaces were not created when EA boundaries split city blocks.