You can also download the Highway Hotline Terminology Fact Sheet in PDF format.
Visibility Conditions
|
Conditions |
Definition |
Visibility Good |
You can see more than 500 metres. |
Visibility Reduced |
You can see between 250 to 500 metres. |
Visibility Poor |
You can see less than 250 metres. Under this condition, Highway maintenance equipment will not begin work on the road until visibility improves. Equipment already on the road may be removed if visibility continues to deteriorate. |
Visibility Zero |
You can see less than 100 metres. Under this condition, Highway maintenance equipment may be removed. |
Primary Conditions
|
Conditions |
Definition |
Bare (Dry/Wet)
|
All wheels of a passenger vehicle are on a bare surface, and some patches of snow and ice may be present.
– Bare and Dry: Most of the road surface is dry.
– Bare and Wet: Most of the road surface is wet.
|
|
Partly Covered |
Two wheels of a passenger vehicle are on a snow or ice-covered surface. |
Covered |
All wheels of a passenger vehicle are on snow or ice. |
Travel Not Recommended |
This means that visibility is less than 250 metres (Poor); and/or highway could become impassable due to road surface conditions (ice, snow, snow drifts, etc.) or extreme weather events. |
Closed |
Highway is impassable (or has been closed for operational reasons or weather). |
Report Not Available |
Unable to report |
|
Secondary Conditions
|
Conditions |
Definition |
Pavement Frost |
Buildup of frost that reduces braking power of vehicles. |
Slush |
A buildup of slush on the driving surface as a result of moderate or heavy snow fall when pavement temperatures are at or near the freezing point creating driving conditions that may cause an unsuspecting driver to lose control of a vehicle. |
Ice |
The driving surface is partly covered or covered with ice. |
Loose Snow |
Less than 8 cm of loose snow partly covers or covers the driving surface that may cause some driving difficulties. |
Heavy Snow |
More than 8 cm of loose snow partly covers or covers the driving surface. Traffic encounters problems when meeting or passing. |
Snow Packed |
The driving surface is partly covered or covered with packed snow. |
Snow Drifts |
Snow drifts exist on the driving surface at intermittent intervals. |
Swirling Snow |
A condition created by traffic in loose snow that reduces visibility. |
Drifting Snow |
Ground drifting caused by winds which may affect surface conditions on the highway, such as sticking snow or may reduce visibility. |
Fog |
Reported only when visibility is reduced. |