Crash Prediction and Risk Evaluation Based on Traffic Analysis Zones

Table 1

Descriptions of TAZ level variables.

Variable name	Definition	𝑁	Mean	Standard deviation	Min	Max
Variables related to; roadway characteristics
LENGTH	Total roadway segment length within a TAZ	733	6.45	7.19	0.30	53.51
ADT	Total roadway average daily traffic within a TAZ	733	212.94	242.17	0.53	2330.21
FFS	Average total roadway free flow speed within a TAZ	733	42.41	9.65	20	76
VMT	Total daily vehicle travelled in a TAZ	733	102	912686	59324.95	72833.07
LANE	Average number of lanes in a TAZ	733	2.86	0.88	2	6
Independent variables related to demographic and economic characteristics
LOW	Number of low income households in proportion to the total number of households	733	0.16	0.15	0	1
LOWMID	Number of middle-low income households in proportion to the total number of households	733	0.22	0.13	0	0.55
MID	Number of middle income households in proportion to the total number of households	733	0.20	0.10	0	0.50
MIDHIGH	Number of middle-high income households in proportion to the total number of households	733	0.22	0.14	0	1
HIGH	Number of high income households in proportion to the total number of households	733	0.13	.13	0	1
BASIC	Number of workers in basic category in proportion to total number of workers in all categories	733	0.21	0.23	0	1
RETAIL	Number of workers in retail category in proportion to total number of workers in all categories	733	0.17	0.20	0	1
TOTALSERVI	Total number of workers in service category in proportion to total number of workers in all categories	733	0.60	0.27	0	1
EMENROLL	Number of students in elementary school in proportion to total number of population	733	0.12	0.33	0	4.34
HSENROLL	Number of students in high school in proportion to total number of population	733	0.05	0.26	0	2.26
COLLENROLL	Number of college students in proportion to total number of population	733	0.05	0.43	0	7.39
POP	Total number of population in a TAZ (in thousands)	733	0.88	0.93	0	8.63
AREA	Area of a TAZ	733	0.01	123.04	3.66	10.65