Responsa for Bava Batra 198:11

אמר רב זביד משמיה דרבא גזירה שמא יתן להן דרך עקלתון רב משרשיא משמיה דרבא אמר בנותן להם דרך עקלתון

<b><i>MISHNAH</i></b>. HE WHOSE FIELD IS TRAVERSED BY A PUBLIC PATH AND HE CLOSED IT, SUBSTITUTING [ANOTHER PATH] AT THE SIDE, FORFEITS THAT WHICH HE HAS GIVEN<span class="x" onmousemove="('comment',' I.e., the new path becomes public property. ');">¹⁹</span> AND [THAT WHICH HE APPROPRIATED AS] HIS DOES NOT PASS INTO HIS POSSESSION.<span class="x" onmousemove="('comment',' And the public may henceforth claim two paths through the field. ');">²⁰</span> A PRIVATE PATH [HAS A WIDTH OF] FOUR CUBITS.<span class="x" onmousemove="('comment',' If a 'private path' has been sold in one's field, a width of four cubits must be allowed for the path. ');">²¹</span> A PUBLIC ROAD [HAS A WIDTH OF] SIXTEEN CUBITS. THE KING'S HIGHWAY HAS NO LIMIT[S]. THE PATH OF A FUNERAL CORTEGE<span class="x" onmousemove="('comment',' Lit., 'the grave'. ');">²²</span> HAS NO LIMIT[S].<span class="x" onmousemove="('comment',' Those following the bier may tread even upon cornfields if their number is so large that the public highway does not suffice. Cf, also n. 5. ');">²³</span> THE HALTING [PLACE]<span class="x" onmousemove="('comment',' The place where, on returning from burial, the funeral escort halts to offer, with due ceremonial, consolation to the mourners. V, infra 100b. ');">²⁴</span> HAD, SAID THE JUDGES OF SEPPHORIS, AN AREA OF FOUR <i>KAB</i>.<span class="x" onmousemove="('comment',' I.e., 50 cubits by 33 1/3, an area sufficient for sowing four kab of seed. ');">²⁵</span> <b><i>GEMARA</i></b>. Why should not [THAT PATH, WHICH HE APPROPRIATED AS] HIS, PASS INTO HIS POSSESSION?<span class="x" onmousemove="('comment',' Surely the path is in his own field and, since he has also substituted another for public use, the public loses nothing. ');">²⁶</span> Let him<span class="x" onmousemove="('comment',' If he cannot prosecute all trespassers. ');">²⁷</span> take a whip and sit down [to guard his path]! Does this, then, imply that a man may not take the law in his own hands even where a loss is involved?<span class="x" onmousemove="('comment',' Surely it has been taught elsewhere that in such a case a man, in self protection, may take the law into his own hands. ');">²⁸</span> — R. Zebid replied in the name of Raba: It is a decree [that he is not allowed to substitute another path for the one already used by the public] lest he assign to them a crooked path.<span class="x" onmousemove="('comment',' Hence the law was enacted that even if one substituted a straight path, no possession could be gained of the old path. ');">²⁹</span> R. Mesharsheya said in the name of Raba: [Our Mishnah deals only with the case where] he gives them a crooked path.<span class="x" onmousemove="('comment',' If, however, he gives the public a straight path, he may take possession of the old one, and use force against any trespassers. ');">³⁰</span>

Teshuvot Maharam