← Paradoxes & riddles
1:49
Braess's Paradox
when a new road makes traffic worse
4,000 drivers travel from Start to End every morning. Route one goes through town A: the first stretch takes (drivers on it)/100 minutes, the second always takes 45 minutes. Route two goes through town B: first a fixed 45 minutes, then (drivers on it)/100 minutes. The drivers split 2,000 and 2,000, and everyone takes 20 + 45 = 65 minutes.
Source: A classic puzzle, retold by INFINITE SUM and fact-checked against our curated notes
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