As BillConner said, there are backgrounds with roads. To change the background, click on the menu in the upper left part of the map, click on Background, and pick one.

I have considered adding them to the default background. To be honest, though, it is pretty low on my list since other backgrounds have it.

I love this site.  I spend a lot of time on here researching routes and dreaming.  One thing that I find myself wishing for every so often when looking for routes in the BW is knowing where the actual roads are.  The Gunflint Trail, Echo Trail, Fernberg Road, roads that lead to outfitters/put-in locations... you get the idea.  Any chance of adding them at some point?