HSIS Variable Name

Name Interpretation

Variable sub classification

Mean

Standard Deviation

Rd_char

The characteristics of the road section where the crash occurred

1) Straight 2) Upgrade 3) Downgrade 4) Horizontal curve

1.673

1.102

Rdsurf

The condition of the road surface where the crash occurred

1) Dry 2) Wet 3) Snowy, or muddy

2.409

0.862

Weather

Weather conditions when the crash occurred

1) Clear 2) Rain 3) Snow, sleet 4) Fog

1.671

0.857

Light

The type of light existed at the time of the crash

1) Daylight 2) Dark, Lights On 3) Dark, No Lights

1.686

0.712

Drv_age

The age of the driver of the vehicle involved

1) <21 years 2) between 21 to 65 3) >65 years

1.772

0.597

Drv_sex

Sex of the driver of the vehicle involved

1) Male 2) Female

1.439

0.521

Vehtype

Type or body of vehicle involved in the crash

1) Passenger Car 2) Van or Minivan 3) Bus 4) Truck

1.218

0.629

AADT

Annual Average Daily Traffic on the crash road section

Numeric values in 1000s of vehicles. Min. = 5.77 Max. = 28.845

14.117

5.587