User:Dsfargeg/Road Types and Zoom Levels
Below are the maximum zoom levels where different road types are visible and selectable. If you select segments and zoom out beyond the selectable boundary for that road type, permalinks you copy will not have those segments selected when the link is loaded by someone else.
NOTE: This is dependent on latitude and screen size in theory. I have tested this at 1366x768 resolution, in Alaska and Pennsylvania, with the same results.
To get the numeric zoom level on your zoom slider like above, install the WME Zoom Level script. The zoom level can also be seen in the "&zoom=" parameter of permalinks.