As at verse 11, the NKJV's "hell" translates Sheol; the rendering affects how the verse is read.
Quick answer
The wise are on an upward road, and the climb itself is what carries them away from the grave below. Direction is the whole point of the picture.
Read both lines
The image is vertical and simple: one road ascends and the alternative descends, and the wise man's ordinary progress is what puts distance between him and the pit. "That he may turn away" states the purpose, which keeps the verse from being a promise about never dying. Everyone in Proverbs' world goes down to Sheol eventually. What the wise avoid is the premature and self-inflicted descent, the death that folly arranges early, and the verse's claim is that wisdom's upward road is not one long escape effort but simply a road that happens to be going the other way.
Why translations differ
"Hell below" renders Sheol here, and the NKJV footnotes the alternative just as it does at verse 11. Sheol is the Old Testament's realm of the dead, the destination of everyone rather than a place of punishment for some, so this verse is contrasting a life that ends well with one that ends early and badly. It is not describing two eternal destinations, and importing that contrast makes the proverb say more than it says.
Related: Proverbs 15:11 · Proverbs 10:27 · Proverbs 4:18
New King James Version®, Copyright © 1982, Thomas Nelson. All rights reserved. Full copyright information. Scripture provided by API.Bible.
Go Deeper
If this verse has been used to put weight on you that it was never carrying, ask about it directly.