How we measure street-network sprawl

The 4 dimensions of SNDi

  • Nodal degree: the number of streets meeting at each intersection
  • Dendricity: the tree-likeness of the network (dead ends and cul-de-sacs)
  • Circuity: the ratio of road distance to straight-line distance between two points
  • Sinuosity: the curviness of individual streets

A higher SNDi means less-connected streets – i.e., more sprawl.

3.43

Global average SNDi

3.11

Global median SNDi

2.15

Amsterdam’s SNDi

Amsterdam has an SNDi of 2.15, which is well-connected.