Man, road and vehicle: risk factors associated with the severity of traffic accidents

Almeida, Rosa Lívia Freitas de; Bezerra Filho, José Gomes; Braga, José Ueleres; Magalhães, Francismeire Brasileiro; Macedo, Marinila Calderaro Munguba; Silva, Kellyanne Abreu

doi:10.1590/S0034-8910.2013047003657

OBJECTIVE

: To describe the main characteristics of victims, roads and vehicles involved in traffic accidents and the risk factors involved in accidents resulting in death.

METHODS

A non-concurrent cohort study of traffic accidents in Fortaleza, CE, Northeastern Brazil, in the period from January 2004 to December 2008. Data from the Fortaleza Traffic Accidents Information System, the Mortality Information System, the Hospital Information System and the State Traffic Department Driving Licenses and Vehicle database. Deterministic and probabilistic relationship techniques were used to integrate the databases. First, descriptive analysis of data relating to people, roads, vehicles and weather was carried out. In the investigation of risk factors for death by traffic accident, generalized linear models were used. The fit of the model was verified by likelihood ratio and ROC analysis.

RESULTS

There were 118,830 accidents recorded in the period. The most common types of accidents were crashes/collisions (78.1%), running over pedestrians (11.9%), colliding with a fixed obstacle (3.9%), and with motorcycles (18.1%). Deaths occurred in 1.4% of accidents. The factors that were independently associated with death by traffic accident in the final model were bicycles (OR = 21.2, 95%CI 16.1;27.8), running over pedestrians OR = 5.9 (95%CI 3.7;9.2), collision with a fixed obstacle (OR = 5.7, 95%CI 3.1;10.5) and accidents involving motorcyclists (OR = 3.5, 95%CI 2.6;4.6). The main contributing factors were a single person being involved (OR = 6.6, 95%CI 4.1;10.73), presence of unskilled drivers (OR = 4.1, 95%CI 2.9;5.5) a single vehicle (OR = 3.9, 95%CI 2,3;6,4), male (OR = 2.5, 95%CI 1.9;3.3), traffic on roads under federal jurisdiction (OR = 2.4, 95%CI 1.8;3.7), early morning hours (OR = 2.4, 95%CI 1.8;3.0), and Sundays (OR = 1.7, 95%CI 1.3;2.2), adjusted according to the log-binomial model.

CONCLUSIONS

Activities promoting the prevention of traffic accidents should primarily focus on accidents involving two-wheeled vehicles that most often involves a single person, unskilled, male, at nighttime, on weekends and on roads where they travel at higher speeds.

[1] Correspondence : Rosa Lívia Freitas de Almeida Departamento de Saúde Comunitária Faculdade de Medicina – UFC Rua Prof. Costa Mendes, 1608 5° andar – Rodolfo Teófilo 60430-140 Fortaleza, CE, Brasil E-mail: rliviafa@gmail.com

Variable	2004		2005		2006		2007		2008		Accidents

	n	%	n	%	n	%	n	%	n	%	n	%

Type of accident
Crash/collision	17,381	76.1	18,074	74.8	18,093	77.2	18,912	79.8	20,387	82.7	92,847	78.1
Running over pedestrian	3,027	13.2	3,160	13.1	2,784	11.9	2,746	11.6	2,366	9.6	14,083	11.9
Fall/leaving road and other	1,441	6.3	1,784	7.4	1,494	6.4	981	4.1	925	3.8	6,625	5.6
Collision with a fixed object	878	3.8	999	4.1	952	4.1	953	4.0	870	3.5	4,652	3.9
Vehicle overturned	126	0.6	155	0.6	120	0.5	108	0.5	114	0.5	623	0.5
Total	22,853	100.0	24,172	100.0	23,443	100.0	23,700	100.0	24,662	100.0	118,830	100.0
Vehicles involved
Only car/truck	9,622	42.1	10,761	44.5	10,267	43.8	10,430	44.0	10,857	44.0	51,937	43.7
Only motorcycles	1,941	8.5	2,238	9.3	2,161	9.2	1,966	8.3	1,852	7.5	10,158	8.5
With motorcycles	3,857	16.9	4,149	17.2	4,299	18.3	4,360	18.4	4,788	19.4	21,453	18.1
Heavy goods vehicles	3,568	15.6	3,396	14.0	3,534	15.1	3,888	16.4	4,678	19.0	19,064	16.0
With bicycles	2,226	9.7	2,328	9.6	2,051	8.7	1,599	6.7	1,552	6.3	9,756	8.2
Various vehicles	1,639	7.2	1,300	5.4	1,131	4.8	1,457	6.1	935	3.8	6,462	5.4
Total		100.0		100.0		100.0		100.0		100.0		100.0
Number of vehicles involved
One vehicle	5,383	23.6	6,013	24.9	5,289	22.6	4,713	19.9	4,177	16.9	25,575	21.5
Two vehicles	16,375	71.7	17,019	70.4	16,984	72.4	17,659	74.5	19,091	77.4	87,128	73.3
More than two vehicles	1,095	4.8	1,140	4.7	1,170	5.0	1,328	5.6	1,394	5.7	6,127	5.2
Total		100.0		100.0		100.0		100.0		100.0		100.0
Type of individual involved
Only driver	16,332	71.5	17,571	72.7	17,442	74.4	18,182	76.7	19,728	80.0	89,255	75.1
Passenger	1,352	5.9	1,211	5.0	1,246	5.3	1,251	5.3	1,113	4.5	6,173	5.2
Pedestrian and/or cyclist	5,169	22.6	5,390	22.3	4,755	20.3	4,267	18.0	3,821	15.5	23,402	19.7
Total		100.0		100.0		100.0		100.0		100.0		100.0
Number of individuals involved
One	2,130	9.3	2,615	10.8	2,269	9.7	1,781	7.5	1,701	6.9	10,496	8.8
Two	18,448	80.7	19,338	80.0	18,860	80.5	19,397	81.8	20,600	83.5	96,643	81.3
More than two	2,275	10.0	2,219	9.2	2,314	9.9	2,522	10.6	2,361	9.6	11,691	9.8
Total		100.0		100.0		100.0		100.0		100.0		100.0
Type of intersection
Crossing	7,121	31.2	7,205	29.8	7,186	30.7	7,170	30.3	7,006	28.4	35,688	30.0
T and double T, Y, roundabout and other	829	3.6	1,002	4.1	1,179	5.0	1,219	5.1	1,233	5.0	5,462	4.6
Level crossing	60	0.3	54	0.2	59	0.3	61	0.3	30	0.1	264	0.2
Mid-block	14,843	64.9	15,911	65.8	15,019	64.1	15,250	64.3	16,393	66.5	77,416	65.1
Total		100.0		100.0		100.0		100.0		100.0		100.0
Jurisdiction
Municipal	21,331	93.3	22,627	93.6	21,907	93.4	21,811	92.0	22,385	90.8	110,065	92.6
State	1,048	4.6	994	4.1	991	4.2	1,122	4.7	1,199	4.9	5,354	4.5
Federal	474	2.1	551	2.3	545	2.3	767	3.2	1,078	4.4	3,415	2.9
Total		100.0		100.0		100.0		100.0		100.0		100.0
Type of road surface
Not asphalt	8,881	38.9	9,336	38.6	8,839	37.2	8,805	37.2	8,489	34.4	44,350	37.3
Asphalt	13,972	61.1	14,836	61.4	14,895	62.8	14,895	62.8	16,173	65.6	74,480	62.7
Total		100.0		100.0		100.0		100.0		100.0		100.0
Light
Daylight	12,481	67.5	13,145	67.0	12,785	66.8	13,246	67.6	14,357	68.9	66,014	67.6
Dawn	767	4.1	857	4.4	822	4.3	839	4.3	648	3.1	3,933	4.0
Dusk	2,213	12.0	2,359	12.0	2,293	12.0	2,218	11.3	2,245	10.8	11,328	11.6
Street lighting	2,224	12.0	2,481	12.7	2,531	13.2	2,629	13.4	2,933	14.1	12,798	13.1
Poor/no illumination	802	4.3	763	3.9	705	3.7	669	3.4	667	3.2	3,606	3.7
Total		100.0		100.0		100.0		100.0		100.0		100.0
Type of signs
Traffic lights	3,491	17.3	4,166	18.6	4,297	19.5	4,291	19.3	4,557	19.4	20,802	18.9
Overhead	3,168	15.7	3,752	16.8	4,212	19.1	4,096	18.4	4,770	20.3	19,998	18.1
Lateral	13,540	67.0	14,452	64.6	13,487	61.3	13,895	62.4	14,170	60.3	69,544	63.0
Total		100.0		100.0		100.0		100.0		100.0		100.0
Time
Morning	6,084	27.2	6,466	27.3	6,223	27.2	6,519	28.0	7,375	30.4	32,667	28.1
Afternoon	7,755	34.6	8,202	34.7	8,100	35.4	8,192	35.2	8,646	35.7	40,895	35.1
Night	6,637	29.6	6,834	28.9	6,525	28.5	6,460	27.8	6,474	26.7	32,930	28.3
Early morning	1,912	8.5	2,143	9.1	2,053	9.0	2,098	9.0	1,741	7.2	9,947	8.5
Total		100.0		100.0		100.0		100.0		100.0		100.0
Week
Monday - Friday	15,334	67.1	15,898	65.8	15,684	66.9	16,314	68.8	17,820	72.3	81,054	68.2
Saturday and Sunday	7,519	32.9	8,274	34.2	7,759	33.1	7,386	31.2	6,842	27.7	37,780	31.8
Total		100.0		100.0		100.0		100.0		100.0		100.0
Day of the week
Wednesday	2,806	12.3	3,015	12.5	2,952	12.6	3,100	13.1	3,482	14.1	15,355	12.9
Thursday	3,110	13.6	3,076	12.7	3,177	13.6	3,141	13.3	3,397	13.8	15,901	13.4
Friday	3,780	16.5	3,711	15.4	3,572	15.2	3,778	15.9	3,996	16.2	18,837	15.9
Saturday	4,085	17.9	4,443	18.4	4,121	17.6	4,093	17.3	3,818	15.5	20,560	17.3
Sunday	3,434	15.0	3,831	15.8	3,638	15.5	3,293	13.9	3,024	12.3	17,220	14.5
Monday	2,912	12.7	3,122	12.9	3,097	13.2	3,270	13.8	3,495	14.2	15,896	13.4
Tuesday	2,726	11.9	2,974	12.3	2,886	12.3	3,025	12.8	3,450	14.0	15,061	12.7
Total		100.0		100.0		100.0		100.0		100.0		100.0
Quarter
January to March	5,042	22.1	5,377	22.2	5,573	23.8	5,351	22.6	5,761	23.4	27,104	22.8
April to June	5,915	25.9	5,982	24.7	5,940	25.3	5,857	24.7	6,305	25.6	29,999	25.2
July to September	5,686	24.9	6,330	26.2	5,844	24.9	5,963	25.2	5,993	24.3	29,816	25.1
October to December	6,210	27.2	6,483	26.8	6,086	26.0	6,529	27.5	6,603	26.8	31,911	26.9
Total		100.0		100.0		100.0		100.0		100.0		100.0

Variable	Traffic accident						OR	95%CI	χ ²	p
	Total		Fatal		No fatality
	n	%	n	%	n	%

Type of accident
Crash/collision	92,847	78.1	760	0.8	92,087	99.2
Running over pedestrian	14,083	11.9	728	5.2	13,355	94.8	6.32	5.71;6.98	1530.95	0.0000
Fall/leaving road and other	6,625	5.6	49	0.7	6,576	99.3	0.90	0.68;1.20	1.92	0.4895
Collision with a fixed object	4,652	3.9	136	2.9	4,516	97.1	3.57	2.98;4.28	182.41	0.0000
Vehicle overturned	623	0.5	25	4.0	598	96.0	4.90	3.32;7.24	24.37	0.0000
Type of vehicles
Only car/truck	51,937	43.7	462	0.9	51,475	99.1
Only motorcycles	10,158	8.5	260	2.6	9,898	97.4	2.88	2.48;3.34	387.77	0.0000
With motorcycles	21,453	18.1	203	0.9	21,250	99.1	1.06	0.90;1.25	136.96	0.0000
Heavy goods vehicles	19,064	16.0	269	1.4	18,795	98.6	1.59	1.37;1.84	1771.98	0.0000
With bicycles	9,756	8.2	343	3.5	9,413	96.5	3.95	3.44;4.17	117.54	0.0000
Various vehicles	6,462	5.4	161	2.5	6,301	97.5	2.80	2.35;3.34		0.0000
Number of vehicles involved
One vehicle	87,128	73.3	745	0.9	86,383	99.1
Two vehicles	25,575	21.5	907	3.5	24,668	96.5	4.15	3.77;4.57	991.56	0.0000
More than two vehicles	6,127	5.2	46	0.8	6,081	99.2	0.88	0.65;1.18	0.74	0.0000
Age of vehicles
Over ten years	32,944	27.7	133	0.4	32,811	99.6
Between six and ten years	23,986	20.2	501	2.1	23,485	97.9	5.17	4.28;6.26	357.85	0.0000
Only vehicles under 5 years	25,810	21.7	452	1.8	25,358	98.2	4.34	3.58;5.26	266.58	0.0000
Location
Crossing	35,688	30.0	302	0.8	35,386	99.2
T, Duplo T, Y, roundabout and other	5,462	4.6	51	0.9	5,411	99.1	1.10	0.82;1.48	1.66	0.5137
Level crossing	264	0.2	19	7.2	245	92.8	8.50	5.44;13.30	7.60	0.0000
Mid-block	77,416	65.1	1.326	1.7	76,090	98.3	2.02	1.79;2.19	128.22	0.0000
Jurisdiction
Municipal	110,061	92.6	1.402	1.3	108,659	98.7
State	5,354	4.5	109	2.0	5,245	98.0	1.60	1.32;1.94	22.95	0.0000
Federal	3,415	2.9	187	5.5	3,228	94.5	4.30	3.70;4.99	423.58	0.0000
Road surface
Not asphalted	44,350	37.3	495	1.1	43,855	98.9
Asphalt	74,880	63.0	1.203	1.6	73,677	98.4	1.44	1.30;1.60	47.72	0.0000
Light
Daylight	65,337	55.0	725	1.1	64,612	98.9
Dawn	4,402	3.7	136	3.1	4,266	96.9	2.78	2.32;3.34	97.97	0.0000
Dusk	11,323	9.5	211	1.9	11,112	98.1	1.68	1.44;1.96	42.24	0.0000
Street lighting	12,759	10.7	217	1.7	12,542	98.3	1.53	1.32;1.78	28.22	0.0000
Poor/no illumination	22,898	19.3	406	1.8	22,492	98.2	1.60	1.42;1.80	36.15	0.0000
Type of signs
Traffic lights	19,998	16.8	160	0.8	19,838	99.2
Overhead	20,802	17.5	185	0.9	20,617	99.1	1.11	0.90;1.37	0.97	0.3249
Lateral	69,544	58.5	1.256	1.8	68,288	98.2	2.26	1.92;2.66	100.99	0.0000
Time
Morning	32,667	27.5	372	1.1	32,295	98.9
Afternoon	40,895	34.4	498	1.2	40,397	98.8	1.07	0.94;1.22	0.97	0.3248
Night	32,930	27.7	554	1.7	32,376	98.3	1.48	1.30;1.68	34.82	0.0000
Early morning	9,951	8.4	274	2.8	9,677	97.2	2.42	2.07;2.82	127.57	0.0000
Week
Monday - Friday	81,054	68.2	956	1.2	80,098	98.8
Saturday and Sunday	37,780	31.8	742	2.0	37,038	98.0	1.67	1.51;1.83	112.59	0.0000
Day of the week
Wednesday	15,355	12.9	165	1.1	15,190	98.9
Thursday	15,901	13.4	186	1.2	15,715	98.8	1.15	0.93;1.41	1.69	0.1931
Friday	18,837	15.9	240	1.3	18,597	98.7	1.19	0.97;1.44	2.88	0.0899
Saturday	20,560	17.3	351	1.7	20,209	98.3	1.59	1.32;1.91	24.84	0.0001
Sunday	17,220	14.5	391	2.3	16,829	97.7	2.11	1.76;2.53	69.21	0.0000
Monday	15,896	13.4	198	1.2	15,698	98.8	1.16	0.94;1.42	1.99	0.1584
Tuesday	15,061	12.7	167	1.1	14,894	98.9	1.03	0.83;1.28	0.08	0.7738
Quarter
October to December	31,911	26.9	432	1.4	31,479	98.6
January to March	27,104	22.8	387	1.4	26,717	98.6	1.05	0.92;1.21	0.59	0.4434
April to June	29,999	25.2	451	1.5	29,548	98.5	1.11	0.97;1.27	2.46	0.1160
July to September	29,816	25.1	428	1.4	29,388	98.6	1.06	0.93;1.21	0.75	0.3867

Variable	Traffic accidents						OR	95%CI	χ ²	p
	Total		Fatal		No fatalities
	n	%	n	%	n	%

Sex of drivers
Only female	10,696	9.0	106	1.0	10,590	99.0
Only male	73,955	62.2	1,249	1.7	72,706	98.3	1.70	1.40;2.08	28.89	0.0000
Both	26,919	22.7	338	1.3	26,581	98.7	1.27	1.02;1.57	4.59	0.0302
Age of drivers
From 25 to 64	63,369	53.3	972	1.5	62,397	98.5
Under 25	27,407	23.1	503	1.8	26,904	98.2	1.20	1.08;1.33	10.87	0.0000
Presence of a driver aged over 65	5,513	4.6	223	4.0	5,290	96.0	2.64	2.29;3.04	187.60	0.0000
Marital status of driver
Married	26,998	22.7	253	0.9	26,745	99.1
Single	23,469	19.8	435	1.9	23,034	98.1	1.98	1.70;2.31	78.41	0.0000
Married and single	41,835	35.2	586	1.4	41,249	98.6	1.49	1.29;1.73	29.29	0.0000
Drivers’ schooling
Only further education	18,665	15.7	107	0.6	18,558	99.4
High school and further education	36,490	30.7	347	1.0	36,143	99.0	1.66	1.34;2.06	50.91	0.0000
Primary education	42,837	36.0	1,166	2.7	41,671	97.3	4.75	3.90;5.78	549.99	0.0000
Type of individual involved
Driver	89,255	75.1	395	0.4	88,860	99.6
Passenger	6,173	5.2	241	3.9	5,932	96.1	8.82	7.53;10.33	1046.09	0.0000
Pedestrian or cyclist	23,402	19.7	1,062	4.5	22,340	95.5	10.25	9.41;11.50	2457.98	0.0000
Number of individuals involved
Two	96,643	81.3	1,206	1.2	95,439	98.8
More than three	11,691	9.8	350	3.0	11,340	97.0	2.40	2.13;2.70	224.61	0.0000
One	10,496	8.8	142	1.4	10,353	98.6	1.08	0.91;1.29	0.84	0.3586
Driving license
Correct license	52,557	44.2	578	1.1	51,979	98.9
Incorrect license	27,902	23.5	598	2.1	27,304	97.9	1.95	1.74;2.18	1.21	0.0000
No license	27,219	22.9	522	1.9	26,697	98.1	1.74	1.55;1.96	19.80	0.0000
Length of time driver has held license
Drivers holding licenses for more than 5 years	53,027	44.6	546	1.0	52,481	99.0
Drivers holding licenses for fewer than 5 years	11,998	10.1	220	1.8	11,778	98.2	1.78	1.52;2.08	54.33	0.0000

Factors	Error

	OR	Standard	z	p	95%

Type of accident
Crash/collision	1
Running over pedestrian	6.31	1.33	8.72	0.0000	4.17;9.55
Fall/leaving road and other	1.27	0.71	0.43	0.6690	0.42;3.83
Collision with a fixed object	5.87	1.69	6.15	0.0000	3.34;10.31
Vehicle overturned	2.38	1.17	1.76	0.0780	0.91;6.23
Day of the week
Wednesday	1
Thursday	1.06	0.16	0.40	0.6910	0.79;1.43
Friday	1.29	0.18	1.78	0.0750	0.98;1.70
Saturday	1.42	0.19	2.60	0.0090	1.09;1.86
Sunday	1.73	0.24	3.98	0.0000	1.32;2.26
Monday	1.11	0.17	0.70	0.4840	0.83;1.49
Tuesday	1.08	0.17	0.51	0.6100	0.80;1.46
Time
Morning	1
Afternoon	1.04	0.10	0.45	0.6510	0.87;1.26
Night	1.33	0.13	2.96	0.0030	1.10;1.61
Early morning	2.36	0.30	6.73	0.0000	1.84;3.03
Jurisdiction
Municipal	1
State	1.45	0.21	2.62	0.0090	1.10;1.92
Federal	2.56	0.34	7.04	0.0000	1.97;3.32
Location
Crossing	1
T, Duplo T, Y, roundabout and other	0.93	0.18	-0.39	0.6970	0.641.35
Level crossing	2.99	1.44	2.26	0.0240	1.16;7.71
Mid-block	1.09	0.09	0.96	0.3350	0.92;1.29
Number of vehicles involved
More than two	1
Two	2.28	0.42	4.41	0.0000	1.58;3.28
One	8.44	2.59	6.95	0.0000	4.62;15.40
Type of vehicles
Only car/truck	1
Only motorcycles	1.77	0.24	4.30	0.0000	1.37;2.30
With motorcycles	3.39	0.46	8.97	0.0000	2.60;4.43
Heavy goods vehicles	2.14	0.33	4.90	0.0000	1.58;2.90
With bicycles	20.89	2.86	22.20	0.0000	15.97;27.32
Various vehicles	1.40	1.01	0.47	0.6420	0.34;5.73
Age of vehicles
Over ten years	1
Between six and ten years	1.63	0.19	4.10	0.0000	1.29;2.06
Only vehicles under five years	1.52	0.18	3.46	0.0010	1.20;1.92
Driving license
Correct license	1
Incorrect license	1.55	0.19	3.63	0.0000	1.22;1.96
No license	0.40	0.07	-5.01	0.0000	0.28;0.57
Length of time drivers have held license
More than five years	1
Fewer than five years	1.09	0.11	0.84	0.3980	0.89;1.33
No license	3.87	0.60	8.68	0.0000	2.85;5.25
Number of individuals involved
Two	1
More than three	2.45	0.58	3.79	0.0000	1.54;3.90
One	6.79	1.65	7.89	0.0000	4.22;10.92
Drivers’ schooling
Only further education	1
High school and further education	1.01	0.13	0.07	0.9420	0.79;1.29
Primary education	2.10	0.25	6.11	0.0000	1.65;2.66
Sex of drivers
Only female	1
Only male	1.48	0.30	1.94	0.0520	1.00;2.20
Both	0.62	0.15	-1.98	0.0480	0.39;1.00
Marital status of driver
Married	1
Single	1.07	0.10	0.76	0.4480	0.90;1.28
Married and single	1.34	0.14	2.79	0.0050	1.09;1.65