This is the best branch of Iman, so preserve it!

Abu Hurirah said that the Messenger of Allah (Peace Be upon Him) said, "Iman has over seventy branches - or over sixty branches - the uppermost of which is the Testimony of Faith: 'La ilaha illallah' (there is no true god except Allah); and the least of which is the removal of harmful objects from the road, and modesty is a branch of Iman."

[Muslim, 35]

Removing harmful objects from the road means to remove them so that people will not get hurt, such as stones, tree branches or thorns etc.