Deuteronomy 19:3 "You shall prepare the way, and divide the border of the land into three parts...that every slayer may flee there"

Nothing happens totally by accident.

A person who unintentionally caused the death of another person must realize that he was also at fault.

He is directed to flee immediately to a "refuge city" set aside for this purpose.

There, he will be safe from the hands of the dead man's relatives who may seek to avenge his death. Also, he will have time to think about what he did and resolve to prevent such "accidents" in the future.

HaShem commands us to set aside such "refuge cities" and enable easy access to them.

We must pave the road leading to the city and remove any obstacle on the way.

This Positive Mitzvah applies in Eretz Yisrael when our entire nation dwells there.