3:3:1 - The criterion of shishim ribo
The text of the Shulchan Aruch reads:
“What is a reshus harabbim? A [street or] marketplace that is sixteen amos wide … and there are those who say [vyeish oimrim] that if it [the (street or) marketplace] does not have 600,000 people traversing it daily [shishim ribo (sixty myriads) ovrim bo b’chol yom], it is not a reshus harabbim.”
Since there is a difference of opinions among the Rishonim, when the Shulchan Aruch (O.C. 345:7) mentions the criterion that the street requires shishim ribo, it prefaces it with a qualifier, “vyeish oimrim,” there are those who say. Subsequently, there is a machlokas haposkim if the Shulchan Aruch maintains that the criterion of shishim ribo can be relied on l’chatchilah.
3:3:2 - Do we accept the criterion of shishim ribo l’chatchilah
The Bais Ephraim rules that relying on shishim ribo is not a matter of following a majority, but only that the criterion was accepted as our minhag in Tzorfas and Ashkenaz. However, since the Mishkenos Yaakov argued that the Magen Avraham and Taz were mistaken in their opinion that the majority of Rishonim maintain that shishim ribo is a fundament of a reshus harabbim (and therefore we do not follow the minhag), the Bais Ephraim presented evidence that the majority of Rishonim accepted shishim ribo.
In fact, we can add to the Bais Ephraim’s tally of Rishonim, since we know today of many more Rishonim who accepted the criterion of shishim ribo [more than 70 accept the criterion and 13 clearly do not]. Hence, we accept the fundament either because this is the minhag or because the overwhelming majority of Rishonim upheld the criterion.
Additionally, many poskim maintain that, notwithstanding the qualifier, “vyeish oimrim,” the Shulchan Aruch does accept the criterion of shishim ribo l’chatchilah. Moreover, there is no doubt that the Rema accepted shishim ribo as a fundament of a reshus harabbim. Consequently, we Benei Ashkenaz who follow the Rema certainly accept the criterion as a fundament of a reshus harabbim, l’chatchilah.
3:3:3 - How the criterion of shishim ribo is applied
From a simple reading of the Shulchan Aruch, it is apparent that the criterion of shishim ribo is conditional of the street.
It was the mesorah through the ages that the criterion of shishim ribo is dependent on a single street. The Divrei Malkiel (4:3) stated when writing to the people erecting an eruv in the city of Odessa, which had approximately shishim ribo, that, “the minhag is to erect eruvin even in the largest of cities and it does not concern us that they contain shishim ribo since the shishim ribo is dispersed over all its streets.”[See more about this issue when we discuss Rav Moshe Feinstein’s shitos in eruvin.]
Furthermore, since the Shulchan Aruch uses the term shishim ribo ovrim bo, it implies a thoroughfare in continuous use and not merely the presence of 600,000 people in the vicinity who would have the ability to utilize the street.
The Bais Yitzchak (Y.D. siman 136:3) responded to one who suggested that the criterion of shishim ribo is not conditional on people actually traversing the road and that their mere presence would be sufficient, “[that] this is in opposition to most poskim including Rashi and Tosfos.”
3:3:4 - How the criterion of shishim ribo applies to Lakewood today
Since the roads of Lakewood are not traversed by shishim ribo, consequently, the streets that are sixteen amos wide fail to meet this criterion, and hence they cannot be deemed as a reshus harabbim, and tzuras hapesachim would suffice to enclose the area.
Following this, it is evident that there is no difference between a Lakewood community wide eruv and the neighborhood eruvin. Both can rely on the fact that the sixteen amos wide roads are not a reshus harabbim since they are not traversed by shishim ribo.
 This is my preliminary list. I will eventually publish a complete list with over 70 Geonim and Rishonim who uphold the criterion and 13 who do not.
Gaonim — 1) Bahag, Berlin edition, p. 131. 2) Rav Amram Gaon, Halachos Pesukos Min HaGaonim, siman 70. 3) Sar Shalom Gaon, Chemdah Genuzah, siman 70 and Sharei Teshuvah, siman 209 (see also Sefer Ha’itim, ois 92). 4) The Gaon mentioned in the Sefer Ha’itim, ois 206.
Rishonim — 5) Rashi, Eruvin 6a, 6b, 26a, 59a, 47a. 6) Baalei HaTosfos, Eruvin 6a, 26a, 59a, and Shabbos 6b, 64b. 7) Sefer Ha’itim, ois 92, 206, 209. 8) Rabeinu Shmuel, Or Zarua, ois 164. 9) Machzor Vitri, Perek B'mah Isha ois 31, 32. 10) Ra’avan, Shabbos 349. 11) HaEshkol, Hilchos Tzitzis ois 31. 12) Ha’itur, Hilchos Tzitzis Shaar 3 Shaar Adom Chelek 1. 13) Ravyah, Hilchos Eruvin 379, 391. 14) HaManhig, Hilchos Shabbos HaTzarichos ois 138. 15) Rokeach, Hilchos Shabbos 175. 16) Sefer HaNer, Eruvin 6a, 59a. 17) Sefer HaTrumah, ois 214, 239. 18) Or Zarua, Hilchos Shabbos siman 16, Eruvin 129. 19) Rid, Piskei Eruvin 6a, 59a, Tosfos Pesachim, 69a and Teshuvos, siman 107. 20) MaHrach Or Zarua, Piskei Eruvin Perek 2 ois 57. 21) Rivevan, Eruvin 6b, 59a. 22) Semag, Hilchos Shabbos p. 17. 23) Maharam MeRotenberg, siman 31, Eruvin ois 9, 10. 24) RaaH, Ran (Hamyuchos), Shabbos 6b. 25) Riaz, Eruvin Perek 1:5, 5:5. 26) Talmid HaRashba, Chiddushei Eruvin 2a, 59b. 27) Mordechai, Shabbos 64b, 100a. 28) Smak, Mitzvos Hatluyos B’Shabbos p. 296, 299. 29) Hagahos Maimonios, Eruvin Perek 5:2, 5:4. 30) Rosh, Beitzah 24a, Eruvin 6a (see also Kitzur Piskei HaRosh, Perek 1:8). 31) Tur, O.C. 345, 364, 392. 32) Ramak, Piskei (Rabeinu Mendel Kloizner) Shabbos 6a, Hagahos Ashri, Eruvin 6b, 20b. 33) Rabeinu Yerucham, Toldot Adom V’Chavah 12:4, 12:17. 34) Orchos Chaim, Hilchos Shabbos ois 284. 35) HaAgudah, Perek 5:56. 36) Tsedah LaDerech, Perek 42, 46. 37) Sefer HaNeyar, Hilchos Eruvin p. 51. 38) Hagahos Ashri, Eruvin 6b, 20b. 39) Nimukei Yosef, Hilchos Tzitzis. 40) HaAgur, siman 537.
The following is a list of Rishonim who oppose the criterion of shishim ribo:
1) Rambam, Hilchos Shabbos 14:1. 2) Hashlama, Eruvin 6a. 3) Ramban, Shabbos 57a, and Eruvin 59a. 4) Sefer HaMeoros, Eruvin 6a. 5) Rashba, Teshuvos HaRashba siman 722. 6) Hagahos Mordechai, Shabbos Perek 6. 7) Ritva, 59a. 8) Magid Mishnah, Shabbos 14:1. 9) Meiri, Bais HaBechirah Shabbos 57a, and Eruvin 6b, and Chidushim Eruvin 6b. 10) Ran, Shabbos Perek 6, Chidushim Eruvin 6a. 11) Rivash, siman 405. [Rabeinu Tam, Rashbam, and Yereim on the Mishkenos Yaakov’s/Misnhnah Berurah’s list of those opposing the criterion are debatable and today can be listed with those who maintain that shishim ribo is a criterion of a reshus harabbim (at least regarding Rabeinu Tam and the Rashbam).]
 While the Mishnah Berurah (Biur Halachah, 345:7, and 364: ) following the Mishkenos Yaakov maintains that the majority of Rishonim upheld that shishim ribo is not a criterion of a reshus harabbim, as mentioned above, their list of Rishonim has been superseded.
 The following is a list of some of the poskim who maintain that the Shulchan Aruch accepted shishim ribo as a fundament of a reshus harabbim: Magen Avraham (345:7); Yad Aharon (345:2); Pachad Yitzchak (erech, Reshus Harabbim); Erech HaShulchan (345:2); Pri Megadim (Aishel Avraham, 345:7, Mishbetzes Zahav, 345:6); Tosfos Chadashim (Shabbos, perek 11:1); Zera Emes (3:41); Sedeh Haaretz (chelek 3, p. 29), and Maharsha Alfandari (O.C. siman 9).
 While the Mishnah Berurah mentions that the Bais Meir questions, what is the Rema’s opinion, the Bais Ephraim (and even the Mishkenos Yaakov) and all the other poskim cite additional proof that the Rema does uphold the criterion of shishim ribo.
 These are some of the additional poskim who clearly maintain that shishim ribo is dependent on the street: Levush (345:7); Perishah (O.C. 325:8); Pnei Yehoshua (Shabbos 5b); Sedei Haaretz (Y.D. p. 29:3); Zera Emes (3:34); Bais Meir (Shabbos 5b); Bais Yaakov (Eruvin 6a); Yad Dovid (Eruvin 55a); Shulchan Aruch HaRav (363:44); Bais Ephraim (p. 46); Mishkenos Yaakov (p. 126); Chiddushi Harim (siman 4); Yeshuos Malko (siman 27); Mishnah Berurah (Shaar HaTzion, 345:25) [the Mishnah Berurah indicates this by the usage of the phrase, “derech hamavoi hamefulash,” ― it is important to note the Mishnah Berurah’s (345:24) primary issue is whether the shishim ribo are required to traverse the street every day of the year or whether occasional use of the street by 600,000 people would be sufficient, see also Toldos Shmuel, 3:86:10]; Minchas Elazar (3:4); Bais Av (2:5:2); Maharshag (2:25); Chazon Ish (107:6); Mahari Stief (siman 68); V’yaan Yoseph (131:1, 155:1, 195:2); Divrei Yatziv (173:4); Rav Shmuel Wosner zt”l (in Shevet HaLevi, 6:41); Rav Yechezkel Roth shlita (in Emek HaTeshuvah 5:19), and see also the shaila to the Chacham Tzvi in siman 37.
 Besides for the above mentioned Bais Yitzchak, the Divrei Chaim (Lekutim siman 3); Yeshuos Malko (O.C. siman 27); Sefas Emes (Shabbos, 6b); Maharsham (3:188); Divrei Malkiel (4:3); Bais Av (2:5:2:3), and Minchas Yitzchak (8:32), all agreed that the criterion of shishim ribo is only met when 600,000 people actually traverse the street.
While it is beyond the scope of this essay, suffice it to say that those who suggest that the Bais Ephraim’s understanding of the Ritva, that the mere presence of shishim ribo in the vicinity would classify a street as a reshus harabbim, are mistaken. The Gedolei Haposkim (mentioned above, the Maharsham, and Minchas Yitzchak) understood the Bais Ephraim otherwise. The only question regarding the Bais Ephraim’s position was whether the requirement of shishim ribo traversing the street was on every day or would on most days suffice.
Furthermore, all those who claim that there are additional poskim who uphold this condition in the criterion of shishim ribo, are incorrect, as all their claims are hearsay posited by the Chevrah Hilchos Issurei Eruvin [while it is beyond the scope of this essay, suffice it to say that all of their arguments have been negated].
 While the Ramban and Piskei Rid, maintain that a sratya would not need to fulfill the criterion of shishim ribo, they clearly state that they are referring to a sratya that is an intercity road, outside of the city boundaries. The few Achronim (Bais Yaakov and Yeshuos Malko) who follow these Rishonim are also referring to an actual intercity road outside of the city limits and only those roads would not need shishim ribo traversing therein to be categorized as a reshus harabbim. However, those poskim who refer to the main road inside of the city limits as a sratya (Bais Ephraim and Avnei Nezer), uphold that it would need to fulfill the criterion of shishim ribo to be classified as a reshus harabbim (besides for maybe Rav Chaim Volozhiner).
Moreover, the overwhelming majority of Rishonim (Rav Amram Gaon, Hilchos Psukos, siman 70; Sar Shalom Gaon, Sharei Teshuvah siman 209; HaEshkol, Hilchos Tzitis, ois 31; Smak, Mitzva 282; Rosh, Beitzah, 3:2; Ritva, Shabbos 6a, and Terumas Hadeshen, siman 55, and the over twenty Rishonim [who state that there is no reshus harabbim today at all, which would include sratyas] and Achronim disagree with the Ramban and Tosfos Rid and maintain that there is no difference between roads inside the city and those that are outside of the city. Both would need to fulfill the criterion of shishim ribo to be classified as a reshus harabbim.
 Even one of the above fundaments would be sufficient ground to permit an eruv of tzuras hapesachim l’chatchilah. Moreover, even if one would allege that according to some Achronim [and contrary to the overwhelming majority of poskim] the above fundaments would not allow an eruv, nevertheless, they would have to agree that each issue is still at the very minimum a safek. Consequentially, we are left with a sfek sfek sfeika, and we would therefore go l’kula even if the matter was a d’Oraysa. Lest one think that sfek sfeika is not utilized in these situations, one should peruse the Yeshuos Malko (O.C. siman 21); Avnei Nezer (O.C. 273:16, 279:2), and Levush Mordechai (4:4).