Road Conditions Terminology

Winter driving is influenced by road and visibility conditions as well as by the presence of snow drifts. Media outlets that report on road conditions use a specific terminology to describe these conditions.

Road conditions over a large part of a given section are what determines the road conditions of the entire section.

Bare and Dry

All tires on a vehicle are on a bare, dry surface.

Bare and Wet

All tires on a vehicle are on a bare, wet surface.

Partly Snow Covered

The tires on one side of the vehicle are on a snowy surface, while the tires on the other side are on a bare surface.

Partly Snow Packed

The tires on one side of the vehicle are on a hard-packed snow surface, while the tires on the other side are on a bare surface.

Partly Ice Covered

The tires on one side of the vehicle are on an ice-covered surface, while the tires on the other side are on a bare surface.

Snow Covered

All tires on a vehicle are on a snow-covered surface.

Snow Packed

All tires on a vehicle are on a hard-packed snow surface.

Ice Covered

All tires on a vehicle are on an ice-covered surface.

Snow Drifts

These are banded accumulations of snow created by wind and blowing snow. They can be present regardless of road conditions and can potentially disrupt travel plans.

Good Visibility

Visibility is greater than 500 m over the entire section.

Reduced Visibility

Visibility varies from 250 to 500 m at specific locations or over a large part of the section.

No Visibility

Visibility is reduced to less than 250 m at specific locations or over a large part of the section.

A snow drift is a large accumulation of snow on the roadway, in more or less narrow bands, caused by wind and blowing snow. For road users, snow drifts are generally localized obstacles and can be present regardless of road conditions.