Table 3.

Summary of variables descriptive statistics.

Variables	Description	Mean	Std. dev	Min	Max
Dependent variables
Severity	1 if severe crashes; 0 if non-severe crashes	0.28	0.45	0	1
Independent variables
Land use
Industrial area	1 if crash occurred in industrial area; 0 otherwise	0.03	0.17	0	1
Residential zone	1 if crash occurred in residential zone; 0 otherwise	0.21	0.41	0	1
Wasteland	1 if crash occurred next to wasteland; 0 otherwise	0.35	0.48	0	1
Roadway characteristics
Faded markings	1 if road markings were faded ; 0 otherwise	0.09	0.29	0	1
Installed barriers	1 if road barriers were installed ; 0 otherwise	0.22	0.41	0	1
Shoulder type	1 if shoulder was paved; 0 if shoulder was unpaved	0.37	0.48	0	1
Traffic variables
Avg speed	Average speed (km/h)	84.16	14.87	36.92	128.37
Log of flow	Logarithmic transformation of flow	2.24	0.60	0	3.32
Pct heavy vehicles	Percentage of heavy vehicles	4.64	9.03	0	42.86
SD speed	Standard deviation of speed (km/h)	7.11	6.08	0	28.48
Weather variables
Temperature	Temperature (degrees of Celsius)	16.27	8.31	− 6.49	40.43