Permeability

Permeability overview

Summary of indicator

Objective

To measure the walking and cycling permeability of the road network, reflecting the walkability and connectivity of an area.

Application guidance

Intersection density is a method of assessing one aspect of a built environment. The density of intersections relays information about street design and connectivity, both of which impact walkability. High intersection density may correspond to more walkable environments that promote healthy lifestyles.

This indicator will support practitioners to understand the extent to which an urban area permits ease of movement for people walking and cycling. Based on the outcome of the analysis, practitioners can determine whether there are ample crossing opportunities for people walking and cycling to access other parts of the network.

Practitioners can use the intersection density metric to measure the number of junction points or nodes available for people walking and cycling.

Metric

Intersection density

Related indicators

	Access and Connection Walking paths Equitable access Steepness
	Comfort and Safety Pedestrian crowding
	Character and Form Street space for pedestrians Legibility

Recommendation

• Additional analysis could be conducted on a project basis to measure the ratio between the area of a 1km walk or cycle from the project site following the current or proposed network versus a 1km polygon from the site
• To enrich the data and analysis, additional data collection of walking and cycling features could be collected, for example a survey of through-site links or mid-block crossings
• Analysis on the type of intersection and presence of facilities that enable walking and cycling could be undertaken to provide a more sophisticated analysis of the value of an intersection in enabling pedestrian and cycling crossing. Intersections that do not provide crossing opportunities for people walking and cycling should be excluded from analysis
• To improve the measurement of connectivity, intersections can be weighted by number of roads links connected and/or road hierarchy. An intersection with more road links has greater connectivity.

Metric in detail