Definition of key terms
The following terms are used throughout the section on Low Salt Design concepts in this manual. Definitions for relevant terms are also highlighted on pages describing each of the ten design strategies that make up Low Salt Design.
- Albedo: the fraction of incident radiation (such as sunlight) that is reflected by a surface or body (such as pavement, snow, or vegetation).
- Critical Area: Area that requires excellent winter friction. Examples of critical areas are front steps, high traffic sidewalks, braking zones, bridges, underpasses, ramps, curves, hills, and ADA routes. The volume of traffic and speed of traffic influence what is deemed as a critical area.
- Fetch: The distance wind blows across water or open land without impedance. For Low Salt Design, look at the prevailing winter wind direction to calculate fetch.
- Horizontal drainage is the near lateral movement of meltwater (meltwater running across a highway ramp) whereas vertical drainage has a more extreme elevation change (i.e., Roof to sidewalk).
- Meltwater footprint: The wet surface area created on a dry pavement from the movement of snowmelt water.
- Meltwater sprawl: The movement of snowmelt onto saltable surfaces.
- Pavement Recovery: The time it takes after snow removal for the pavement to regain traction that meets user expectations. Several of the Low Salt Design strategies help here. This could also refer to the time it takes after a freezing rain event to regain traction that meets user expectations.
- Plowability: A way to rate the site for ease or difficulty of motorized snow removal.
- Plowshed: Delineated surface from where snow is pushed into a snow pile.
- Precision Winter Maintenance: Winter maintenance strategies that minimize the amount of salt to meet the level of service targets.
- Salt: Generic term that represents chloride-based deicers.
- Saltable surfaces: Includes sidewalks, parking lots, roads, trails, bridges, ramps, and steps, most outdoor hard surfaces that are used for walking or driving in cold climates.