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

Table 1

Descriptive statistics of the final dataset, 58 815 segments.

Parameter		Number of segments	% of segments	% of total length	% of accidents
Lane width	1.5–1.75 m	2347	3.99	3.94	2.13
	1.76–2.0 m	3402	5.78	5.81	2.13
	2.01–2.25 m	5284	8.98	8.92	3.19
	2.26–2.5 m	6351	10.80	10.92	6.91
	2.51–2.75 m	9075	15.43	15.44	11.17
	2.76–3.0 m	15,558	26.45	26.50	33.51
	3.01–3.25 m	12,183	20.71	20.67	27.13
	3.26–3.5 m	4615	7.85	7.81	13.83
Shoulder width	0–0.25 m	15,611	26.54	26.94	32.45
	0.26–0.5 m	25,037	42.57	21.44	45.21
	0.51–0.75 m	12,644	21.50	42.49	16.49
	0.76–1.0 m	3549	6.03	5.91	4.26
	> 1 m	1974	3.36	3.22	1.60
Region	East	20,115	34.20	33.71	45.21
	Middle	9259	15.74	15.38	8.51
	North	16,426	27.93	28.93	14.89
	South	4576	7.78	7.75	10.64
	West	8439	14.35	14.23	20.74
Road type	European	7164	12.18	12.52	14.36
	County	47,123	80.12	79.67	76.60
	District	4528	7.70	7.81	9.04
AADT	< 500	25,514	43.38	43.73	23.40
	501–1500	18,851	32.05	31.85	35.64
	1501–4000	11,319	19.25	19.23	31.38
	4001–6000	1914	3.25	3.22	4.79
	6001–8000	601	1.02	0.99	1.06
	> 8000	616	1.05	0.98	3.72
% of long vehicles	< 8%	11,172	19.00	18.61	16.49
	8–12%	29,599	50.33	50.06	51.60
	> 12%	18,044	30.68	31.34	31.91
Speed limit	60 km/h	8934	15.19	14.58	13.83
	70 km/h	2611	4.44	4.33	4.26
	80 km/h	47,270	80.37	81.09	81.91