We don’t want to go down that road, do we?
I have two questions concerning this sentence:
“… laggiù su …” sounds somewhat redundant like “… down on that road…”.
Is it really neccessary?
The English sentence might be used figuratively, e.g. one student proposes to go to the lake instead to the lecture and the other says “…” (okay, not a realistic secenario but … lasciatemi sognare).
Can the Italian sentence also be used in that way?
Interesting questions indeed, curious to see the responses to this one.
On first read, I’m reading “laggiù” as “down there”, but that’s not reflected in the English sentence at all (and would exclude a potential figurative interpretation), so something like “We don’t [/wouldn’t] want to go down that street down there, do [/would] we?”
Without laggiù would it not just indicate “We don’t want to go on that road, do we?” Laggiù makes it much more descriptive and emphases "down there that road… ". Just my two cents;-)
It makes me think of a back seat driver giving advice, as I read the Italian sentence as “we don’t want to go down there on that road do we?” (we should take the A1 instead, then we’ll avoid the roadworks… 
)
(Ah yes, and then if you take the spur road up the A? and swing onto the M?? avoiding the second turnoff up the M?, it’ll cut at least 2 minutes off your trip…) grrrr!
As an Italian native speaker, I would most likely interpret the English sentence in the figurative sense.
In any case, even if the sentence were to be interpreted literally, the Two versions do not match.
I would use: “Non vogliamo prendere questa strada, vero?” but I don’t think this has the strong figurative sense that is present in the English sentence. I mean, it could be used in a figurative sense, but I wouldn’t think that is the main meaning.