Constructing indices representing supportiveness of the physical environment for walking using the Rasch measurement model

Table 2 Means, standard deviations, minima, maxima, and point-biserials for individual environmental indices and environmental scales scores

Variables	Mean	SD	Min	Max	r_pbis¹	r_pbis²
*Functional*	*20.44*	*3.56*	9	30
Traffic control devices	0.94	1.08	0	4	.73	.64
Crossing devices	1.86	1.08	0	4	.69	.56
Crossing aids	2.07	0.99	0	4	.70	.56
Road width	0.93	0.25	0	1	.37	.32
Path/road condition	1.03	0.59	0	2	.12	.24
Traffic volume	1.67	0.63	0	2	.53	.42
Traffic speed	0.99	0.12	0	1	.19
Street pattern	1.43	0.79	0	2	.17	.18
Alternative routes	0.30	1.77	0	1	.20	.31
Intersection design	0.19	0.39	0	1	.15	.19
Path continuity	0.73	0.44	0	1	.14	.21
Slope of path/road	1.68	0.56	0	2	.12	.22
Intersection distance	0.19	0.39	0	1	.10
Street lights present	1.07	0.40	0	2	-.12
Street surveillance	1.66	0.62	0	2	.27	.27
Destinations present	0.35	0.48	0	1	.11	.27
Path location	1.57	1.27	0	3	.18	.15
Driveway crossovers	0.09	0.29	0	1	-.10
*Aesthetics*	*12.34*	*2.79*	1	18
Verge maintenance	1.51	0.68	0	2	.50	.63
Garden maintenance	1.64	0.63	0	2	.50	.62
Cleanliness	1.79	0.45	0	2	.43	.52
Attractiveness	1.01	0.47	0	2	.49	.51
Views	2.50	1.08	0	4	.40	.39
Trees	3.54	1.79	0	5	.68	.59
Alikeness of buildings	0.34	0.47	0	1	.16	.20

¹ Initial point-biserial correlation
²Point-biserial correlation after category rescoring and variable reduction (r_pbis < 0.15)

ISSN: 1479-5868