goldersgreener:
“Although the מחבר clearly says ששים רבוא עוברים בכל יום nonetheless many פוסקים including ר’ משה felt that his intent was undoubtedly עיר שיש בה שיים רבוא as it said in Rashi. If I understood right, R; Shimon eider, and ylach”t R’ meir rosner שליט”א feel that I the road was intended to serve 600,000, even if not necessarily at the same time or even day it constitutes a רשות הרבים דאורייתא.
It is not many poskim at all. Rav Moshe would not subscribe to R’ Meir Rosner argument. On the contrary he would disagree with R’ Rosner’s chiddushim. Rav Moshe maintains that the possibility that we should have 600,000 people traversing the streets of a 12 mil by 12 mil area, could only be if there are 3 million people living or commuting therein. On the contrary, Rav Moshe argues that we do not include those who are inside, and not traversing the streets. Hence if a city only has a population of 600,000 Rav Moshe would not classify it as a reshus harabbim, since shishim ribo needs to traverse the streets themselves.
Furthermore, Rav Moshe agreed that the Shulchan Aruch is referring to a street, and therefore, he claimed that the SA is denoting a sratya, in which case Rav Moshe agrees that the shishim ribo needs to traverse the street itself to be classified as a reshus harabbim.
I don’t believe that Rav Eider agreed with R’ Rosner.
To understand why Rashi make use of the word city in reference to the criterion of shishim ribo, we need to reference Rashi in Eruvin 59b:
דרך עיירות להיות פתחי פילושיהן לאורכם ורה”ר עוברת מפתח לפתח וחלוקה לאורכה … והני דרסי בהך רה”ר … ורה”ר זו מחברתם שכולם מעורבין בה
Rashi is informing us as to how cities were designed. Cities in the past had a main road that all residents used to enter and exit the city (because most cities were walled), and this thoroughfare was the reshus harabbim of the city. Consequentially, when Rashi and the Rishonim who follow him use the word city in reference to shishim ribo, they are not signifying that the criterion is conditional on a city but only that the main thoroughfare in a city containing shishim ribo would be classified as a reshus harabbim since it is traversed by its entire population.
In any case, where do we see that to accept the simple meaning of the Sulchan Aruch is considered novel?
“I think that they have always expressed concerning London that even if one makes various strings and צורות הפתח one is nevertheless transgressing an איסור דאורייתא and is חייב כרת.”
They made use of mechitos that are omed merubeh al haparutz. Those who still require that one should be stringent is treading on thin ice.