Traffic jam

A more natural way to express this concept in English would be: "If there's a traffic jam, it's a good idea to take a detour."

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Sure! In simpler language you could say: "If the road is too busy, it's smart to go a different way."

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Absolutely, here's a simpler expression with those words: "If lots of cars are on the road, it's good to go a different way." or "If there's a lot of cars, it's better to take a different road."