Не ищи проселочной, когда есть столбовая

Do not neglect the experience of others, profit from it

Cf:

A beaten path is a safe one (Am.). The beaten road is the safest (Am., Br.). Don't leave a travelled road to follow a trail (Am.). Don't quit the highway for a short cut (Br.). Don't take unnecessary risks (Br.). The highway is never about (Am.). Keep the common road and you are safe (Am.)