I've seen this sign around Madrid for several years now, and it never fails to bother me. Why? "Gran Vía Street" is redundant. A "Vía" is a kind of street, so it doesn't make any sense to say it twice.
Generally speaking, you do not need to translate place names. The Plaza Mayor is the Plaza Mayor. Cibeles is Cibeles, not Cibelle Place. If an English speaker asks for directions, say the name in Spanish. That's what's printed on the maps the Tourism Office gives out.