Safety Effects of Horizontal Curve Design and Lane and Shoulder Width on Single Motorcycle Accidents in Norway

Table 5

Results of the statistical analysis. Significant results presented in bold font.

Parameters		Significance	Odds ratio	95.0% CI for the odds ratio
				Lower	Upper
Lane width	1.5–1.75 m	0.383	0.518	0.118	2.271
	1.76–2.0 m	0.015	0.208	0.059	0.738
	2.01–2.25 m	0.196	0.476	0.155	1.467
	2.26–2.5 m	0.592	0.806	0.366	1.776
	2.51–2.75 m	0.272	0.703	0.375	1.318
	2.76–3.0 m	0.383	1	1	1
	3.01–3.25 m	0.547	0.859	0.525	1.407
	3.26–3.5 m	0.973	0.989	0.520	1.880
Shoulder width	0–0.25 m	0.881	1	1	1
	0.26–0.5 m	0.836	1.047	0.680	1.611
	0.51–0.75 m	0.525	0.837	0.483	1.450
	0.76–1.0 m	0.702	0.817	0.290	2.302
	>1 m	0.514	0.622	0.150	2.586
Region	East	0.343	1	1	1
	Middle	0.304	0.691	0.341	1.398
	North	0.041	0.546	0.305	0.975
	South	0.730	0.885	0.444	1.765
	West	0.659	0.892	0.536	1.483
Road type	County	0.591	1	1	1
	European	0.951	1.022	0.520	2.008
	District	0.351	0.721	0.362	1.435
Heavy vehicles	<8%	0.653	0.883	0.512	1.521
	8–12%	0.838	1	1	1
	>12%	0.783	1.075	0.644	1.792
Curve type + High/low + Adjacent curves	Straight	0.000	1	1	1
	Single curve + low	0.013	10.739	1.653	69.754
	Single curve + high	0.863	0.922	0.367	2.318
	Multiple opposite dir.	0.000	21.993	8.465	57.141
	+ High + NOT OK
	Multiple same dir.	∗	∗	∗	∗
	+ High + NOT OK
	Multiple opposite dir.	0.000	3.341	2.010	5.552
	+ Low + NOT OK
	Multiple same dir.	0.012	2.582	1.228	5.430
	+ Low + NOT OK
	Multiple opposite dir.	0.000	14.063	6.213	31.833
	+ High + OK
	Multiple same dir.	0.000	12.442	3.744	41.346
	+ High + OK
	Multiple opposite dir.	0.000	4.970	2.752	8.974
	+ Low + OK
	Multiple same dir.	0.054	2.420	0.984	5.952
	+ Low + OK

^∗Only one segment had this specific categorization