If you were talking about a printed map I would think about it this way...
On a very finely drawn map, a line would appear to be about 0.2mm width, this equates to a pixel size of 10m (0.2 X 50,000 / 1,000). Then there are all the other things to consider, generalization and detail at that scale.
But if that's what you've got, go with it. Just be aware of the potential pitfalls.
Good luck, Neil