Some area's won't be allowed to use salt, I know in Issaquah in Washington state they could not use salt upon the roads due to laws to protect the salmon streams.
Probably a fair few area's in which salt is prohibited for road use due to such things. So sand makes sense and for some that is all they will see in their area.
How much persistent snow does Washington state get though? The discussion is most relevant for places where snow falls and will stay where it is for months if something is not done.
> How much persistent snow does Washington state get though?
At elevation, of course there's some that's persistent, but that's not much of the state at all. eg Crystal Mountain has snow in the winter, but is completely bare by the summer.
That is pretty ironic that salmon are at risk of salt given they are famous for adjusting to the ocean. Even though they are essentially already terminally ill and falling apart when they head back into the river to spawn.
Probably a fair few area's in which salt is prohibited for road use due to such things. So sand makes sense and for some that is all they will see in their area.