[On Transferring Graves for Public Interests]

Answer—and Allah is the One who grants success: If it is unavoidable that the route pass there, then exert your utmost to divert it away from the cemetery. If you are unable to do so, then transfer the graves over which the route would pass to another place—and you will, Allah willing, have a reward in that.
When you transfer the graves, do so while preserving their sanctity: bury each grave separately, do not mix them; gather the bones and soil of each grave and bury them; do not excavate them with a backhoe or loader, due to the lack of reverence entailed in that.
(This question came from some students of Wādī ʿAlāf.)
We add a further benefit:
The evidence for the obligation to preserve the sanctity of a Muslim believer’s grave is as follows:
1. Presumption of continuity of the sanctity due to the believer in life; the default is the persistence of that sanctity, and there is no evidence that it lapses at death.
2. His saying, Exalted is He: “We will surely take over them a place of worship,” [al-Kahf:21] which plainly indicates honoring the believer and observing his sanctity in death.
3. Muslims, generation after generation, have observed this sanctity.
4. The Sunnah has come commanding the observance of this sanctity.
On this basis, any act that contravenes the sanctity of the deceased is prohibited—such as treading on the grave with one’s feet and taking it as a pathway, placing shoes upon it, or dumping refuse and sweepings upon it, or sitting on it, and anything of that nature that signals contempt and belittlement.
Source : Min Thimār al-ʿIlm wa al-Ḥikmah vol.1