StreetFilms’ Clarence Eckerson, Jr., shows how the alternate side dance can slow traffic.

On alternate side of the street parking days, many communities in
Brooklyn have worked out a deal so car owners are allowed to double
park without impunity so the streets can get their weekly brushing.
(Okay, let’s not touch that argument today.) During the interim
switchover when drivers are relocating their cars – usually lasting
about 15 to 20 minutes – chicanes are temporarily created, which
delightfully slow car speeds to more human levels.