Winter Road Terminology
You can also download the Highway Hotline Terminology Factsheet in PDF format.
Condition | Definition |
---|---|
Closed | Highway is impassable (or has been closed for operational reasons or weather). |
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. |
Heavy Snow | More than 8 cm of loose snow covers the driving surface. Traffic encounters problems when meeting or passing. |
Ice Covered | The entire driving surface is covered with ice. |
Icy or slippery sections | A minor situation identified due to intermittent rain, frost, sticking snow or ice patches (includes light pavement frost). |
Loose Snow | Less than 8 cm of loose snow covers the driving surface that may cause some driving difficulties. |
Pavement Frost | Build-up of frost that reduces braking power of vehicles. |
Seasonal Driving | No specific problems however there could be the occasional condition. |
Slush | A build up 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. |
Snow Drifts | Small snow dunes exist on the driving surface at intermittent intervals. |
Snow Packed | This condition exists mainly on gravel roads where the entire driving surface is covered with packed snow. |
Swirling Snow | A condition created by traffic in loose snow that reduces visibility. |
Travel Not Recommended | This means that visibility is less than 250 metres (poor); and/or the surface is icy; and/or the highway is doubtful; and/or the highway may be blocked. |
Visibility Good | You can see more than 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 Reduced | You can see less than 250 to 500 metres. |
Visibility Zero | You can see less than 100 metres. Under this condition, highway maintenance equipment may be removed. |
Wet/freezing | Highway is wet, subject to freezing as temperatures drop. |
Winter Conditions Exist | If conditions other than seasonal driving are reported, it automatically shows winter conditions exist (yellow line on the map). This may include icy, slippery sections or swirling snow. |