Opinion by

The plaintiff’s injury was caused by a fall occasioned by his striking his foot against the edge of a paving stone which projected above the adjoining stones in the sidewalk of a much used but poorly lighted street. The instruction in relation to the duty of the borough to supervise its sidewalks and to maintain them in a reasonably safe condition was free from error except the part covered by the sixth assignment of error. This part of the charge left it to the jury to fix a standard for the maintenance of sidewalks and to find the borough negligent if there had been a failure to come up to their conception of what a sidewalk ought to bé. The law fixes the standard of duty as reasonable care, and it cannot be left to the judgment or caprice of a jury to establish any other standard. The necessity for and the plan of municipal improvements are matters within the discretion of the municipal authorities. The question of necessity is never for a jury, and the question as to the plan is not whether the best and safest plan has been adopted but whether that adopted is reasonably safe ; and reasonable safety, as in the case of machinery and methods, is to be determined by the standard of ordinary usage: Borough of Easton v. Neff, 102 Pa. 474; Cauavan v. Oil City, 183 Pa. 611. The *359same rule applies as to the duty of maintenance. The question in this case was whether the pavement was reasonably safe. This was to be determined by the standard of ordinary usage and not by a standard the jury might set up.

The sixth specification of error is sustained, and the judgment is reversed with a venire facias de novo.