delivered the opinion of the Court:
Prior to the revision of the statutes, in 1874, the-doctrine as held in this State was, that where a highway had been obstructed after having been opened and traveled by the public, the proper remedy was by prosecution, under the statute, against the party causing the obstructions, and not by mandamus to compel the commissioners of highways to remove the obstructions and open the road. (Commissioners v. People, 73 Ill. 203; Commissioners v. People, 66 id. 339; People v. Curyea et al. 16 id: 547.) The ground upon which the doctrine was chiefly placed was, that there being a complete and adequate remedy by indictment, relief by mandamus was precluded; and another ground stated in some of the eases was, that no statute expressly imposed upon the commissioners the duty of removing such obstructions. .
The ground there is another remedy equally convenient and effectual, and therefore mandamus did not lie, is abrogated by section 9 of the act to revise the law in relation to mandamus, in force July 1, 1874, which provides that “the proceedings for the writ of mandamus shall not be dismissed nor the writ denied because the petitioner may have another specific legal remedy, where such writ will afford a proper and sufficient remedy. ” Whether or not mandamus will lie since the revision of 1874, and under the present road laws, against highway commissioners, to .compel the removal of obstructions from a public road, and if so, under what circumstances it will lie, does not appear to have been passed upon by this court.
*489The second section of the act of 1883 in regard to roads and bridges in counties under township organization, provides that the commissioners of highways shall have charge of the roads and bridges of their respective towns. Section 71 of the act provides as follows: “If any person shall injure or obstruct a public road by felling a tree or trees in, upon or across the same, or by placing or leaving any other obstruction thereon, or encroaching upon the same with any fence, or by plowing or digging any ditch or other opening thereon, or by turning a current of water so as to saturate or wash the same, or shall leave the cuttings of any hedge thereon for more than ten days, they shall forfeit for every such offense a sum not less than three dollars nor more than ten dollars; and in case of placing any obstruction on the highway, an additional sum of not exceeding three dollars per day for every day he shall suffer such obstruction to remain after he has been ordered to remove the same by any of the commissioners, complaint to be made by any person feeling himself aggrieved. * * * And provided further, that the commissioners, after having given reasonable notice to the owners, or person so obstructing or plowing or digging ditches upon such road, of the obstruction, may remove any such fence or other obstruction, fill up any-such ditch or excavation, except ditches necessary to the drainage of an adjoining farm, emptying into a ditch upon the highway, and recover the necessary cost of such removal from such owner or other person obstructing such road aforesaid, to be collected by said commissioners before any justice of the peace having jurisdiction.” Section 74 provides for the recovery of fines and penalties in the name of the town, and that it shall be the duty of the commissioners to seasonably prosecute for all fines and penalties under the act, and that “in case of a failure of such officers to so prosecute, complaint may be made by any person, provided said person shall, before bringing suit in the name of the town, give a bond for costs, as is provided for in the case of non*490residents. But whenever any person shall enter complaint to any commissioner, it shall be the duty of such commissioner to at once proceed to .investigate as to the reasons of such complaint, and if such complaint is found to be just, he shall at once proceed to prosecution.”
The averments of the petition are not based upon the failure of the commissioners to sue for the fines and penalties imposed by section 71, but upon their neglect and refusal to remove the fence from the public road, and the only relief prayed for is a writ commanding them “to proceed to have said obstruction removed, as is their duty according to law. ”
It is urged, that as the commissioners have charge of the roads in their town, they have a discretion in respect to the matter of their management, and that the courts will not coerce them, by mandamus, in regard to matters that are placed under their control and left to their discretion. Many of the powers given to the commissioners are discretionary, but, in our opinion, the power here in question is not of that character. By section 2 of the act it is made their duty to keep the roads of their town in repair, and section 5 requires them to exercise such care and supervision over such roads as the public good may require. The language of section 71 is, “that the commissioners, after having given reasonable notice, etc.,, may remove any such fence or other obstruction,” etc. We think it was intended by the statute to impose upon the commissioners the imperative duty of removing obstructions from the public highway, and that the word “may” is to be construed as “shall.” The word “may,” in a statute, will be construed to mean “shall” whenever the rights of the public or of third persons depend upon the exercise of the power or the performance of the duty to which it refers, and such is its meaning in all cases where the public interests and rights are concerned, or a public duty is imposed upon public officers, and the public or third persons have a claim de jure that the power shall be exercised. Kane v. Footh, 70 Ill. 587; Fowler v. Pirkins, *49111 id. 271; Gillinivater v. M. & A. R. R. Co. 13 id. 1; Schuyler County v. Mercer County, 4 Gilm. 20.
In the statute before us it is clear that a duty is imposed upon public officers, and that the rights and interests both of the public and of third persons are involved, and that they have a claim, as matter of right, that the highway commissioners should exercise the power given them, and the duty devolved upon them of keeping the public road clear and free from fences or other obstructions that render it impossible to travel thereon. It is to be noted that the statute provides the fences or other obstructions are to be removed by the commissioners after they have given the notice mentioned therein. The number of days’ notice thus to be given is not designated, and it is only required it shall be a reasonable notice. There is, then, necessarily some discretion in the commissioners, in this regard. The duty on them to act is imperative, and the discretion given them is merely in respect to a matter which is incidental to the performance of such duty. It is as much incumbent upon the commissioners to exercise this merely incidental discretion, for the public good, by determining what is a reasonable notice in the particular case, and by giving it, as it is to remove the obstruction from the road. When a discretion is abused, and made to work injustice, it is admissible that it shall be controlled by mandamus. Village of Glencoe v. People, 18 Ill. 382; Tapping on Mandamus, (Am. ed.) 66.
The claim is made by appellees, that the court can not tell, from the petition, whether they, appellees, in removing the fence, would be trespassers or not, and that the ease is like the case of Comrs., etc., of Yorktown v. People, 66 Ill. 339. At the time of that decision there was no statute which expressly imposed upon commissioners of highways the duty of removing obstructions in a highway. Besides this, the obstructions in that case were of long standing, were maintained under a claim of right by land owners, and were believed by the road authorities not to be within the limits of the highway. Here, *492the truth of all the averments in the petition is admitted by the demurrer, and the conceded facts are, that the fence and obstruction are across an existing public highway that has been used as such for more than twenty years, and that such obstruction makes it impossible to travel such highway. It is not perceived how it is possible, under such circumstances, the commissioners, in proceeding to remove the fence in conformity with the provisions of the statute, could be trespassers. The writ of mandamus, ever since the revision of the statute relating thereto, is only issued in a ejear case, and in the discretion of the court. (People v. Weber, 86 Ill. 283.) If, therefore, another case should arise which is like the Yorhtown case, supra, where the alleged obstruction is maintained by a third person under a claim of right, and is believed by the commissioners not to be within the highway, perhaps the court might, under its discretionary power, refuse the writ of mandamus, and leave the petitioner to the remedy by indictment, without he had, •by a suit prosecuted by him in the name of the town, under the privilege given him by section 74 of the Boad and Bridge act of 1883, first established, as against the person maintaining the supposed obstruction, that the locus in quo was in fact a part of the public highway.
Various minor objections are made to the petition. Suffice it to say, that we do not regard them as well made, and that, in our opinion, it shows a good prima facie case for the awarding of a writ of mandamus.
Our conclusion is, that it was error in the circuit court to sustain the demurrer to and dismiss the petition. The judgments of the circuit and Appellate courts are reversed, and the cause remanded to the circuit court.