Road condition (METRo)
From Documentation
Contents |
[edit] Code
In the road forecast file, the value of road contidion (<rc>) means the following:
| Description | METRo value | NTCIP code equivalent | SSI code equivalent | Lufft IRS21 Code equivalent |
|---|---|---|---|---|
| Road condition | ||||
| Dry road | 1 | 3 | 33 | 0 |
| Wet road | 2 | 4,5,6 | 34,36,39,41,42 | 1,2 |
| Ice/snow on the road | 3 | 7,8,9,10 | 35,37,38 | 3,4 |
| Mix water/snow on the road | 4 | |||
| Warning | ||||
| Dew | 5 | 12 | ||
| Melting snow | 6 | |||
| Frost | 7 | 13 | 40,43 | |
| Icing rain | 8 | |||
[edit] Interpretation
[edit] Road condition
[edit] Dry road (1)
Each reservoirs (water and ice/snow) contains less than 0.2 mm of liquid water equivalent.
[edit] Wet road (2)
The water reservoir contains more than 0.2 mm of water.
[edit] Ice/snow on the road (3)
The ice/snow reservoir contains more than 0.2 mm of water equivalent.
[edit] Mix water/snow (4)
Both of the reservoirs (water and ice/snow) contains more than 0.2 mm of water equivalent.
[edit] Warning
[edit] Dew (5)
Condensation on the road when the temperature of the surface of the road is above the freezing point.
[edit] Melting snow (6)
Solid precipitation on the road when the temperature of the surface of the road is above the freezing point.
[edit] Frost (7)
Condensation on the road when the temperature of the surface of the road is under the freezing point or water already present on the road turning into ice.
[edit] Icing rain (8)
Liquid precipitation on the road when the temperature of the surface of the road is under the freezing point.
[edit] Criteria for determination of the road condition
For every timestep (currently 30 seconds), METRo determines the road condition based on the table at the bottom of the page. For every period (currently 20 minutes) of the road forecast of METRo, the maximum value reached during this period is used to designate it.
As example, if the values for the 20 minutes are:
[1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 5, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1]
the value 5 will designate this period.
Note: The threshold value used in the table have the value 0.2 mm in the case of the liquid reservoir and 0.2 cm in the case of the snow/ice reservoir.
| Criteria | Value | METRo code |
|---|---|---|
| Water and snow/ice reservoirs contains less than their threshold and there is no condensation | Dry road | 1 |
| Water reservoir contains more than the threshold | Wet road | 2 |
| Snow/ice reservoir contains more than the threshold | Ice/snow | 3 |
| Water and snow/ice reservoirs contains more than the thresholds | Mix water/snow | 4 |
| Water and snow/ice reservoirs contains less than the thresholds, presence of liquid condensation and no rain | Dew | 5 |
| Presence of snow precipitation when the temperature of the surface of the road is above the freezing point | Melting snow | 6 |
| Water and snow/ice reservoirs contains less than the thresholds, presence of solid condensation and their is no transfer between the snow/ice and water reservoir | Black ice | 7 |
| Presence of rain and the temperature of the surface of the road is below the freezing point | Icing rain | 8 |
| METRo I/O files |
| Station | Observation | Forecast | Roadcast | Configuration |
| METRo I/O specification |
| Schema | | Flowchart | Format | Date | Observation QA/QC | Road condition | Station type | Time zone | Layer type | Latitude and longitude |
| METRo I/O examples |
| Station | Observation | Forecast | Roadcast | Graphical display |
 | This page is part of the documentation of the METRo software. Back to the table of content. |
