Environmental Determinants of Bicycling Injuries in Alberta, Canada

Table 3

Matched and un-matched logistic regression estimates of the association between environment risk factors and MV/bicyclist collisions.

	Matched OR	95% CI	Adjustment factors	Un-matched OR	95% CI	Adjustment factors
Traffic volume
Low^a	1	Reference	^b	1	Reference	^b
Med^a	5.13*	1.44, 18.27	Riding fast	3.49*	1.37, 8.88	Age
High^a	2.34	0.75, 7.24	Riding fast	2.83*	1.24, 6.42	Age
High speed limit (>30 km/hr)	3.18	0.62, 16.41	^b	2.59	0.87, 7.71	^b
Land use
Offices	8.8	0.99, 78.16	^b	3.01	0.73, 12.36	Age, day/time and riding fast
Retail	5.56*	1.72, 17.98	Age	7.54*	3.15, 18.03	Age and speed
Industry	2.07	0.28, 15.43	^b	3.70	0.48, 28.82	Age and speed
Services	3.80*	1.29, 11.69	^b	2.02	0.96, 4.23	Age
Nature	0.38	0.14, 1.00	Speed	0.44*	0.21, 0.91	^b
Path characteristics (side 1)
Type of path
Sidewalk	1	Reference		1	Reference
No path	1.66	0.14, 19.75	Age	1.30	0.43, 3.89	Speed
Multi-use path^#	0.63	0.16, 2.51	Age	1.05	0.41, 2.68	Speed
Path location (distance from road)
Within 1 m	1	Reference		1	Reference
Btw 1 and 3 m	1.02	0.26, 3.95	Sex	0.40	0.14, 1.12	Age and day/time
>3 m	0.17	0.02, 1.53	Age	0.16	0.02, 1.29	Age and day/time
Sloped path	1.60	0.35, 7.36	^b	1.14	0.35, 3.71	Riding fast
Path obstructions	1.05	0.38, 2.93	Age	1.80	0.88, 3.70	^b
Path characteristics (side 2)
Type of path
Sidewalk	1	Reference		1	Reference
No path	0.38	0.12, 1.26	Riding fast	0.68	0.28, 1.68	Age and speed
Multi-use path^#	0.61	0.10, 3.78	Riding fast	1.69	0.59, 4.85	Age and speed
Sloped path	0.15	0, 1.99	^b	0.72	0.18, 2.98	Day/time, riding fast and speed
Path obstructions	3.83*	1.03, 14.25	^b	2.59*	1.13, 5.90	Speed
Roadway characteristics
Designated bike lane	0.64	0.10, 4.19	^b	1.83	0.42, 8.02	Day/time, riding fast and age
Parking restrictions	3.88*	1.31, 11.55	^b	1.74	0.85, 3.55	Age
Curb
Mountable	1	Reference		1	Reference
Not mountable	3.03*	1.04, 8.82	Sex	1.35	0.65, 2.82	Riding fast
No curb	0.84	0.13, 5.59	Sex	0.55	0.12, 2.56	Riding fast
Curb cuts	2.71	0.84, 8.72	^b	0.82	0.38, 1.78	Riding fast and age
Traffic control devices	2.74*	1.02, 7.35	Riding fast	1.59	0.74, 3.45	Age and day/time
Intersection	6.89*	1.48, 32.14	^b	2.83*	1.11, 7.20	Age
Crossings	1.68	0.62, 4.54	^b	1.54	0.73, 3.26	Age and day/time
Crossing aids	0.4	0.10, 1.52	^b	0.43	0.16, 1.18	Age and speed
Safety characteristics
Street lights (side 2)	2.38	0.51, 10.99	^b	1.54	0.43, 5.58	Age
Lighting over path (side 2)	1.03	0.30, 3.53	^b	1.70	0.69, 4.16	^b
Destinations	2.4	1.01, 6.00*	Sex	2.35*	1.11, 4.97	Riding fast
Aesthetic characteristics
>1 tree/block (side 1)	3.25	0.37, 28.46	^b	1.71	0.63, 4.63	Riding fast
Tall trees (side 1)	2.27	0.26, 20.06	^b	1.08	0.21, 5.45	Riding fast
Natural views	0.2*	0.07, 0.69	Age	0.43*	0.21, 0.86	^b
Difficult for bicycling	2.00	0.68, 5.92	^b	1.92	0.55, 6.66	Speed and day/time

MV: motor vehicle; OR: odds ratio; CI: confidence interval.
*Represents significance based on CI not including the null value.
^aLow volume: ≤250 vehicles/hr, medium volume: 250–749 vehicles/hr, high volume: ≥750 vehicles/hr.
^bIf model could not accommodate the addition of one or more covariates or there was no evidence of confounding, the crude estimate was retained.