| Background value |
| Energy production site in urban area |
| Energy production site outside urban area |
| Nonroad imp in urban area |
| Nonroad imp outside urban area |
| Primary road in urban area |
| Primary road outside urban area |
| Secondary road in urban area |
| Secondary road outside urban area |
| Tertiary road in urban area |
| Tertiary road outside urban area |
| Thinned road outside urban area |