Severe injury in multiple impacts: Analysis of 1997–2015 NASS-CDS

Figures & data

Table 1. Nonejected driver distribution and injury risks by belt use and number of impacts using 1997–2015 NASS-CDS (MY 1997+ vehicles, age 15–104).

	Number of impacts
	Single	2	3	4+	Total
Vehicles	32,998,791	8,566,067	2,195,676	1,128,984	44,889,518
	MAIS 0+F
All	17,268,455	5,375,856	1,627,028	778,624	25,049,962
Belted	13,720,725	4,339,101	1,274,456	594,630	19,928,913
Unbelted	2,605,916	874,768	285,159	167,718	3,933,561
	MAIS 4+F
All	62,364	53,954	27,063	23,793	167,174
Belted	35,153	24,473	11,209	12,615	83,449
Unbelted	25,127	28,028	14,951	10,309	78,415
	MAIS 4+F risk
All	0.361%	1.004%	1.663%	3.056%	0.667%
SE	0.064%	0.271%	0.389%	0.778%	0.145%
Belted	0.256%	0.564%	0.880%	2.121%	0.419%
SE	0.031%	0.079%	0.125%	0.646%	0.059%
Unbelted	0.964%	3.204%	5.243%	6.147%	1.993%
SE	0.265%	1.316%	1.776%	1.559%	0.621%
Belt effectiveness	73.4%	82.4%	83.2%	65.5%	79.0%

Table 2. Single impact distribution and nonejected driver injury risks by crash type and belt use using NASS-CDS 1997–2015 (MY 1997+ vehicles, age 15–104).^a

	Impact type in single-event crashes
Single impact	Front	Left (near)	Right (far)	Rear	Rollover	Other/unknown	Total
Vehicles	17,738,325	4,071,507	3347872	6,585,710	546,055	709,322	32,998,791
	MAIS 0+F
All	11,011,178	2,346,339	1,958,022	1,218,553	392,106	342,257	17,268,455
Belted	8,606,905	1,884,556	1,607,027	1,020,837	345,154	256,246	13,720,725
Unbelted	1,772,687	331,111	262,100	137,671	45,409	56,938	2,605,916
	MAIS 4+F
All	37,009	12,119	6,520	1,142	4,078	1,496	62,364
Belted	18,426	8,800	3,802	1,012	2,336	777	35,153
Unbelted	17,279	2,968	2,457	81	1,742	600	25,127
	Risk MAIS 4+F
All	0.336%	0.517%	0.333%	0.094%	1.040%	0.437%	0.361%
SE	0.057%	0.091%	0.087%	0.020%	0.480%	0.127%	0.064%
Belted	0.214%	0.467%	0.237%	0.099%	0.677%	0.303%	0.256%
SE	0.018%	0.084%	0.071%	0.024%	0.250%	0.114%	0.031%
Unbelted	0.975%	0.896%	0.937%	0.058%	3.836%	1.054%	0.964%
SE	0.272%	0.206%	0.273%	0.023%	2.733%	0.230%	0.265%
Belt effectiveness	78.0%	47.9%	74.8%	−69.5%	82.4%	71.2%	73.4%

^a Highlighted cells have unwgt samples < 10.

Table 3. Two-impact crash distribution and injury risks by crash type for belted, nonejected drivers using NASS-CDS 1997–2015 (MY 1997+ vehicles, age 15–104).^a

		Front				Left (near)				Right (far)
First impact
Second impact	Front	Left (near)	Right (far)	Rear	Front	Left (near)	Right (far)	Rear	Front	Left (near)	Right (far)	Rear
Vehicles	1,257,264	695,866	645,941	300,027	264,265	538,385	179,559	46,567	337,850	241,647	446,615	85,187
MAIS 0+F	618,020	423,235	370,264	131,071	138,404	318,351	108,637	24,670	249,797	173,623	14,328	149,568
MAIS 4+F	2,478	1,353	1,301	863	1,779	3,521	1,001	511	1,009	330	225	538
Risk MAIS 4+F	0.401%	0.320%	0.351%	0.658%	1.285%	1.106%	0.921%	2.073%	0.404%	0.190%	1.568%	0.360%
se	0.057%	0.110%	0.060%	0.271%	0.351%	0.440%	0.369%	1.322%	0.102%	0.070%	0.931%	0.147%
	Rear
First impact
Second impact	Front	Left (near)	Right (far)	Rear	Rollover	Total
Vehicles	1,843,506	74,931	51,788	28,915	1,106,665	8,566,067
MAIS 0+F	565,247	21,114	33,490	7,011	700,385	4,339,101
MAIS 4+F	566	154	307	69	5,301	24,473
Risk MAIS 4+F	0.100%	0.731%	0.916%	0.980%	0.757%	0.564%
Second impact	0.058%	0.383%	0.804%	0.802%	0.101%	0.079%

^a Highlighted cells have unwgt samples < 10.

Figure 1. Risk of severe injury (MAIS 4+) for belted drivers in a frontal crash as the first impact.