Bava Batra 100A

רב אשי אמר: כל מן הצד ⁠– דרך עקלתון היא; קרובה לזה, ורחוקה לזה.

Rav Ashi said: Any alternative path on the side of the original path is considered a circuitous route, as it is close for this person and it is far for that person. While some will benefit from the change, it will be detrimental to others. Therefore, one may never exchange a public path for an alternative path.

ולימא להו: שקלו דידכו והבו לי דידי! הא מני ⁠– רבי אליעזר היא. דתניא, רבי יהודה אומר משום רבי אליעזר: רבים שבררו דרך לעצמם, מה שבררו בררו.

§ The Mishnah teaches that if a field owner provides an alternative thoroughfare through his field for the public to use, the public may use both thoroughfares. The Talmud suggests: But let him say to them: Take your original thoroughfare back and give me my thoroughfare that I provided you. The Talmud answers: In accordance with whose opinion is this Mishnah? It is in accordance with the opinion of R' Eliezer, as it is taught in a baraita that R' Yehuda says in the name of R' Eliezer: If the public selected a thoroughfare through a privately owned field for themselves even without gaining the permission of the field owner, that which they selected, they selected, and they have the right to use it.

לרבי אליעזר ⁠– רבים גזלנים נינהו?! אמר רב גידל אמר רב: כגון שאבדה להן דרך באותה שדה.

The Talmud asks: According to the opinion of R' Eliezer, are the members of the public entitled to be robbers? Why should they be permitted to appropriate land from a private owner? Rav Giddel said that Rav said: R' Eliezer refers only to a case where the public lost a thoroughfare in that field, e.g., the field was plowed over and the original course of the thoroughfare is not known. In such a case, the public has the right to determine the course anew.