Accessibility

Accessible via Processing > Cityseer > Accessibility. Computes land-use accessibility by counting reachable features (from a point or polygon data layer) within distance thresholds along the street network.

Input Parameters

Parameter	Description	Default
Street network line layer	A line layer in a projected metre-based CRS	(required)
Data layer	A point or polygon layer containing land-use features	(required)
Land-use category field	Text column containing the land-use category for each feature. If not set, all features are treated as one category.	(none)
Distance thresholds	Comma-separated distances in metres	400,800
Max assignment distance	Maximum distance (metres) to snap data points to the nearest street segment	400
Use simplest path (angular)	Use angular (simplest) paths instead of shortest (metric) paths on the internally constructed dual graph	False
Boundary polygon	Optional polygon layer. Nodes inside the boundary are used as sources; nodes outside provide network context only.	(none)
Decay expression	Advanced. Distance-decay weighting for the counts. Default 1 counts all reachable features equally.	1
Time thresholds	Advanced. Comma-separated minutes; overrides distances when set. Converted to metres using the walking speed.	(none)
Walking speed	Advanced. Metres per second, used to convert minutes to distances.	1.33

Land-Use Categories

If a land-use field is selected, the dialog provides a Load categories button that reads unique values from the selected field. Individual categories can then be checked or unchecked. Categories are unchecked by default; use Select all to enable all categories, or check specific ones. Only text (string) columns are available for the land-use field.

If no land-use field is selected, all features are counted together under a single category (all).

Output

The output is a line layer with the original street segments and computed accessibility values as attributes. For each land-use category and distance threshold, two types of columns are produced:

cc_<category>_<distance>[_ang]                  -> count of reachable features within the threshold
cc_<category>_nearest_max_<max_distance>[_ang]  -> distance to nearest feature

For example, with a type field containing pub and shop, and distances 400,800:

• cc_pub_400, cc_pub_800
• cc_pub_nearest_max_800
• cc_shop_400, cc_shop_800
• cc_shop_nearest_max_800