R' Yosef Gavriel Bechhofer gave a shiur this week in Passaic on the
topic of the use of power/telephone wires for city eruvin.
He shared an interesting chiddush of the Tzitz Eliezer about rishus
ha'rabim. When it comes to defining a rishus ha'rabim of 600,000 people,
Rav Waldenberg said that people in cars don't count. That would mean that
a street like Ocean Parkway would not be a rishus ha'rabim according to
Rav Waldenberg.
Video of the shiur is at
https://rygb.blogspot.com/2023/01/the-use-of-powertelephone-wires-for.html