The most important thing for a map at the local level is that it be conformal - that is, shape-preserving.
If the angle between two roads is 38 degrees, the angle should be 38 degrees on your map. Mercator is conformal.
Area distortions aren't a big deal, because on a local level, they only have the effect of scaling the map by an overall factor. You have to zoom in more to see features of a given size at the equator than at high latitudes, but that's not such a big problem.
Another nice feature of Mercator is that it's cylindrical, so when you zoom out, the map fits on a rectangular screen.
If the angle between two roads is 38 degrees, the angle should be 38 degrees on your map. Mercator is conformal.
Area distortions aren't a big deal, because on a local level, they only have the effect of scaling the map by an overall factor. You have to zoom in more to see features of a given size at the equator than at high latitudes, but that's not such a big problem.
Another nice feature of Mercator is that it's cylindrical, so when you zoom out, the map fits on a rectangular screen.