Table 3 Definitions and calculation formulas of the three selected space syntax metrics

Integration

\(I=\frac{2\left({D}_{M}-1\right)}{n}\) (5)

\(G=\frac{I}{{D}_{M}}\) (6)

\({D}_{n}=\frac{n\left[{\log }_{2}\left(1-\frac{{D}_{M}}{n}\right)\right]-1}{\left(n-1\right)\left(n-2\right)}\) (7)

In the formula,\(\,I\) is the global integration, \(n\) is the total number of axes or nodes, \(G\) is the local integration value, \({D}_{M}\) is the average depth value, \({D}_{n}\) is the standardized parameter, and \(n\) is the total number of axes.

Measures the centrality of a street within the system.

Choice

\(C=\frac{{\log }_{2}\left(\frac{1}{{\alpha }_{0}+10{\alpha }_{0}}{\sum }_{i=1}^{n}{\sum }_{j=1}^{n}{\sigma }_{{ij},j+1}\right)}{{\log }_{2}\left[{\sum }_{i=1}^{n}d({x}_{i})+3\right]}\) (8)

In the formula, \(C\) is the choice, \(i\ne x\ne j\), \(d(x,i)\) is the shortest distance from \(x\) to \(j\) in the axial space, and \(\sigma (i,x,j)\) is the shortest topological path from \(i\) to \(j\) in the axial space.

Reflects the frequency of a street being used as a through-movement path.

Intelligibility

\(\mathrm{Intelligibility}={{\rm{R}}}^{2}\) (9)

In the formula, \({R}^{2}\) is the determination coefficient.

Represents the intelligibility of the global network from its local spatial structure.