Translation:Besides, it is not a main highway.
Whatsmore isn't really used in English that much so while it isn't wrong as the idea is correct, besides, or moreover work better.
A small correction -- the correct way to write the expression is "What's more"
Not sure if "by the way" is wrong or whether I got marked wrong for saying "main road" instead of "main highway" or both.
I was marked wrong for 'Besides, it is not a main street.' I've been using 'street' for 'carretera' on DuoLingo this whole time. Shouldn't this be accepted?
I used "highway" instead of "main highway", as a highway is per definition a main road.
to me, a non native English speaker who might be wrong, "there is no main road" sounds like there are only alleys or badly constructed road or things like that in an area, while "it is not a main highway" is a description towards a specific road. Además, there is would be hay and the whole sentence would become "Además, hay no carretera principal." But, like I said at the beginning I might be wrong, so it would be great if there are native speakers (English or Spanish) to help us out :)
You need to use hay to say that something exists (or doesn't). Estar and ser are both copulas, they're basically used to describe or give information about a known subject. So in this sentence, es means you're describing a particular road
Further instead of furthermore doesn't work? Ugh, sometimes this system is so frustrating.