Are our Reshuyot today considered Reshut Harabim? I know it goes both ways, yet, what is the majority view, and most importantly why?
Is an eruv valid for a Reshut harabim De’Oraytah?
What are the parameters of the eruv?
The Gemara states that a tzuras ha-pesach based eruv (not full walls) is only effective for a karmelis, and not for a reshus ha-rabim (Torah public domain).
The three criteria mentioned by the Gemara for a public domian are:
(a) Minimum width of sixteen (16) amos (approx. 28 feet)
(b) No obstruction overhead
(c) No obstructions at either end of the area.
According to this classification, the great majority of streets in any metropolitan city would rate as a public domian, and actual physical walls (or doors that close) would be the only means through which an eruv could be generated.
However, our eruvin today rely on the opinion of Rashi, which is that a reshus ha-rabim requires a minimum of six hundred thousand people (600,000) traversing it each day (or that the city should have 600,000 residents, as the Rosh understood it). Although many rishonim disagree with this (see Biur Halachah 345), it is noteworthy that many also concur, as the Beis Efraim (26) notes.
Although the Beis Yosef appears to rule in favor of the Rambam (and not Rashi), he does mention Rashi’s opinion, and several later poskim (including the Magen Avraham and the Taz — though the Taz concludes by stating that a G-d fearing Jew will not rely on it) rely on this opinion for the construction of eruvin.
As we know, the common custom today is to rely on eruvin.