definitions

Term	Description
Dry:	The road is free of puddles and standing water.
Wet:	There are puddles and standing water present; spray coming off cars.
Slick:	Long, continuous sections of icy or snow packed roads. Greater than 50% of road section is icy or snow packed.
Slick in Spots:	Short, non-continuous sections of icy or snow packed road. Less than 50% of road section is icy or snow packed.
Drifted Snow:	Drifts of any size that cross the white line and cause a driver to feel a bump or a pull on the steering wheel.
Snow:	Snow in excess of an isolated or occasional shower with the potential to stick to the road surface.
Rain:	In excess of light showers with potential to make the road surface wet.
Strong Wind:	Winds greater than 25 mph on slick roads or 35 mph on dry roads.
Fog:	Fog that impairs visibility to less than 400 feet.
Blowing Snow:	Snow propelled by the wind across or along the road surface at least 1 foot above the ground.
Limited Visibility:	Visibility less than 400 feet for any reason.
Chain Law	A link to Wyoming Highway Patrol's definition of the chain law.
No Unnecessary Travel:	The road is open but travel is not recommended due to hazardous driving conditions. Generally, this advisory is posted during winter months due to extremely icy conditions, when visibility is limited due to blowing snow, or when a combinations of conditions makes travel ill-advised. Only the most urgent of situations should warrant travel in a No Unnecessary Travel advisory. Drivers who attempt such travel should be familiar with local conditions and be very experienced with winter driving. Please keep in mind that by choosing to travel during hazardous conditions, you may be interfering with maintenance personnel and their efforts to improve highway safety.