Braess's Paradox (opens in new tab)

https://news.ycombinator.com/item?id=1594478 Aug 2010 (48 comments) - dead link, "Removing street signs, lights and arrows increases safety and road capacity"

This would fall under "veridical paradox" - true statement which most people would expect to be false.

If that diagram was electrical resistors, then adding that middle path across the bridge would never increase the resistance from A to B and therefore reduce the current. At worst, the added resistor will do nothing (because the nodes of the Wheatstone bridge are at the same potential). If any current flows at all across the new connection, it improves the flow.

>In Seoul, South Korea, a speeding-up in traffic around the city was seen when a motorway was removed as part of the Cheonggyecheon restoration project.[2] In Stuttgart, Germany after investments into the road network in 1969, the traffic situation did not improve until a section of newly-built road was closed for traffic again.[3] In 1990 the closing of 42nd street in New York City reduced the amount of congestion in the area.[4] In 2008 Youn, Gastner and Jeong demonstrated specific routes in Boston, New York City and London where this might actually occur and pointed out roads that could be closed to reduce predicted travel times.[5]