Safety Evaluation for Highway Geometric Design Based on Spatial Path Properties

Table 5

Crash rate and spatial curve properties of different roads.

No.		Curvature			Torsion
		1	0.095	0.001789	0.005869	3.281	0.00000825	0.00012100	14.667
2	0.159	0.001538	0.004338	2.821	0.00000609	0.00007141	11.717
3	0.113	0.001325	0.003220	2.430	0.00000452	0.00003959	8.751
4	0.021	0.000279	0.000143	0.512	0.00000023	0.00000132	5.870
5	0.030	0.000391	0.000280	0.717	0.00000039	0.00000156	3.965
6	0.235	0.002537	0.011804	4.653	0.00001990	0.00031290	15.723
7	0.036	0.000626	0.002054	1.148	0.00000289	0.00004235	5.133
8	0.067	0.001252	0.004108	2.297	0.00000578	0.00008470	10.267
9	0.111	0.001077	0.003037	1.975	0.00000426	0.00004999	8.202
10	0.079	0.000928	0.002254	1.701	0.00000316	0.00002771	6.126
11	0.015	0.000195	0.000100	0.358	0.00000016	0.00000092	4.109
12	0.021	0.000274	0.000196	0.502	0.00000027	0.00000109	2.776
13	0.165	0.001776	0.008263	3.257	0.00001393	0.00021903	11.006
14	0.138	0.000746	0.001456	1.367	0.00000235	0.00020209	6.014
15	0.214	0.001989	0.010369	3.648	0.00001457	0.00025531	12.268
16	0.099	0.000645	0.001089	1.182	0.00000153	0.00000722	3.306
17	0.235	0.001519	0.006713	2.496	0.00003528	0.00025823	10.732
18	0.197	0.001065	0.002080	1.953	0.00000336	0.00028870	8.591
19	0.305	0.002842	0.014813	5.212	0.00002081	0.00036473	17.526
20	0.141	0.000921	0.001556	1.689	0.00000219	0.00001032	4.723
21	0.336	0.001899	0.009590	3.566	0.00005040	0.00036890	15.332

Note.  = crashes per million vehicle-kilometers;  = average;  = standard deviation;  = coefficient of variation.