Glossary purpose: crews and supervisors often use the same words for different surface conditions, and the plow pass depends on which one it is. Direct answer: the terms below are working definitions used in the field, not official standards. Agree your own definitions in your depot, and confirm by looking, probing and testing safely. I give no temperature or friction figures.
Glossary
| Term (working meaning) | How it often looks and feels | How to confirm safely | What it may mean for the plow pass |
|---|---|---|---|
| Loose snow | Soft, shifts when driven on | Look and kick the surface | Normal plowing |
| Packed snow | Snow compressed by traffic into a firm layer, often white or grey | Scrape a small area with a boot or shovel and see if it lifts in a sheet | May need a more aggressive edge or a treatment to break the bond |
| Packed ice | Hard, glossy or dull layer bonded to pavement | Scratch with a tool; it chips rather than crumbles | Edge may skim over it; edge wear can be high if forced |
| Black ice | Thin, clear ice that looks like wet pavement | Look for gloss, check the temperature trend with caution, and treat any shine as slippery | Plowing does little; treatment and caution matter more |
| Frost layer | Thin white coating of frozen moisture on cold surfaces | Look at the surface at dawn and on bridges | Plow does not remove it; treat if needed |
| Ice film | Thin film left after a pass or from refreeze | Look at where the edge has smeared a surface | Check edge, speed and treatment timing |
Using the glossary
A glossary is only useful if everyone uses the same words the same way.
- Agree the terms in a depot briefing and show example photographs from your own area.
- Use the same words in reports, so that “packed ice” always means the same thing.
- When in doubt, describe what you see in plain words in the log.
- Never test a surface by walking on a live road.
Limits
Surface conditions change quickly, and a layer can look different in daylight and darkness. These definitions are a communication tool, not a measurement.
A shared photo set
Build a small shared album of labelled photographs from your own area, with a short caption for each. New drivers and supervisors can learn the vocabulary in half an hour, and arguments about what counts as packed ice become easier to settle.
Boundary: These are informal field terms and not official definitions; no temperatures or friction values are given.
Further reading on this site.
What Packed Ice Does to a Standard Cutting Edge ↗Setting Up an Edge for Packed Ice ↗Packed ice carbide kit ↗Scraping First, Salting Second: Sequencing on Lots and Walks ↗Slush Plowing: Why Edges Skim and What Crews Adjust ↗Low-Visibility Plowing: Why Setup Matters for Edges ↗
