I'd think valid tags would look like this: **access=yes**&ensp;&emsp;&emsp;&emsp;&emsp;&emsp;&emsp;&emsp;{it is legally accessible to all} **smoothness=impassable**&emsp;{it is impassable to vehicles} I can't predict how The access tag is optional. The OSM default is to assume any route is full access.<br><br> Conditionals like "IF the snow is deep enough THEN a routing engine will deal with that. snowmobile can use this route" are beyond me. See [https://wiki.openstreetmap.org/wiki/Conditional_restrictions][1] for the current practice on conditionals. [1]: https://wiki.openstreetmap.org/wiki/Conditional_restrictions

I'd think valid tags would look like this: **access=yes**&ensp;&emsp;&emsp;&emsp;&emsp;&emsp;&emsp;&emsp;{it is legally accessible to all} **smoothness=impassable**&emsp;{it is impassable to vehicles} I can't predict how a routing engine will deal with that.