Investigation of Contributing Factors to Traffic Crashes and Violations: A Random Parameter Multinomial Logit Approach

Table 2

Descriptive statistics of possible variables influencing the traffic violations by seriousness.

Variable description (number of observations = 34019)		Total		Unintentional violations		Minor violations		Serious violations		Crash with violation
		N	%	N	%	N	%	N	%	N	%
Individual factors
Race/ethnicity	Asian driver	2463	7.24	161	5.2	2104	7.98	142	3.81	56	6.69
	Hispanic driver	8757	25.74	947	30.57	6145	23.31	1439	38.62	226	27
	African American driver	10,675	31.38	1051	33.93	8383	31.8	1015	27.24	226	27
	Caucasian driver	12,124	35.64	939	30.31	9726	36.9	1130	30.33	329	39.3
Gender	Male driver	22,383	65.80	2220	71.66	16,646	63.15	2956	79.33	561	67
	Female driver	11,636	34.20	878	28.34	9712	36.85	770	20.67	276	33
Residence of driver	Non-Maryland	61	0.18	4	0.13	50	0.19	7	0.19	0	0
	Maryland	33,958	99.82	3094	99.87	26,308	99.81	3719	99.81	837	100
Commercial license	Commercial license	781	2.30	84	2.71	560	2.12	112	3.01	25	2.99
	Noncommercial license	33,238	97.70	3014	97.29	25,798	97.88	3614	96.99	812	97
Temporal factors
Time of day	Morning peak (7–9 a.m.)	2706	7.95	231	7.46	2306	8.75	98	2.63	71	8.48
	Off-peak (9 a.m.–4 p.m.)	10,956	32.21	854	27.57	9672	36.69	225	6.04	205	24.5
	Afternoon peak (4–6 p.m.)	2833	8.33	316	10.2	2276	8.63	146	3.92	95	11.4
	Evening (6–10 p.m.)	4549	13.37	658	21.24	3332	12.64	392	10.52	167	20
	Nighttime (10 p.m.–7 a.m.)	12,975	38.14	1039	33.54	8772	33.28	2865	76.89	299	35.7
Season	Spring	7346	24.11	661	21.34	5591	21.21	895	24.01	200	23.84
	Summer	9049	25.66	764	24.67	7088	26.89	981	26.34	216	25.78
	Fall	8675	23.88	847	27.33	6737	25.56	890	23.89	201	24.02
	Winter	8949	26.35	826	26.66	6943	26.34	960	25.76	221	26.36
Road factors
Work zone	Work zone	12	0.04	0	0	11	0.04	1	0.03	0	0
	Nonwork zone	34,007	99.96	3098	100	26,347	99.96	3725	99.97	837	100
Socioeconomic factors
Commute mode	The percentage of driving to work of the driver’s residence area	0.79	0.10	0.78	0.10	0.79	0.1	0.77	0.1	0.76	0.1
	The percentage of public transportation to work of residence area	0.18	0.09	0.19	0.09	0.18	0.09	0.2	0.09	0.21	0.09
	The percentage of walking to work of residence area	0.03	0.02	0.03	0.02	0.03	0.02	0.03	0.02	0.03	0.02
Commute travel time	Mean travel time to work of the driver’s residence area	34.31	2.45	34.16	2.05	34.31	2.53	34.43	2.21	34.25	2.19
Income level	Median household income of the driver’s residence area (10,000 US dollars)	9.62	2.91	9.45	2.85	9.75	3.02	9.08	2.22	9.25	2.48