The town where the speed limit sign has been wrong for 40 years on purpose

A small town's speed limit sign has displayed a limit ten miles below the road's legal maximum for over four decades, a discrepancy the town openly acknowledges and has no plans to fix, because the wrong number produces exactly the driving behavior the actual limit failed to.

The real, legal limit produced frequent accidents at a sharp curve just past the sign. The intentionally wrong number slows drivers enough before the curve that accidents dropped sharply after the sign went up, despite technically posting inaccurate information the whole time.

Traffic engineers elsewhere have quietly studied the town's approach, even though it technically violates standard signage practice. Sometimes the wrong number is the one that actually works.

Part of the deeper dive: The Collection of True Stories Too Strange to Make Up.