TT #198 · Parashas Shoftim · Fifth Aliyah · Passuk 19:03
You shall prepare the way for yourself, and divide into three the border of your land that the Eternal your God will cause you to inherit, and it shall be for every killer to flee there.
Torah Temimah points to Sifrei Devarim 181.
TT lemma: תָּכִין לְךָ הַדֶּרֶךְ.
English: ‘You shall prepare the way’ – so that the cities not be far from settlement.
Derash on accessibility (Sifrei) — the preparation includes ensuring reasonable proximity.
The cities of refuge must be reachable; the roads and placement are arranged so that flight is practical.