@how.stuff.happens: Why Merging Early Makes the Jam Worse Zipper merge vs early merge: in a jam, the driver who rides the open lane to the cone is doing it right. The federal sign manual describes a late merge that uses all available lanes until the merge point at the lane closure taper, where drivers take turns (MUTCD 11th ed. 6N.19 and 6H.08). And the RIGHT LANE CLOSED 1 MILE sign is an advance warning that a lane ends ahead, not an order to merge now (MUTCD 2009 ed. 6F.22, sign W20-5). FHWA says early merging is the status quo because it looks more courteous, but it leaves one lane packed and the other empty. Pennsylvania's DOT developed the late merge to cut road rage (Colorado DOT late merge overview, 2015), and Minnesota's DOT warns that last-second lane switching can lead to serious crashes and road rage. Missouri's DOT says the zipper cuts the length of backups by 40-50 percent. The catch: it only pays off in slow, stop-and-go traffic. When traffic moves at the speed limit, Missouri and Minnesota both say to merge early. And in Washington, it is illegal for a driver in the open lane to actively block merging traffic (WSDOT). Work zone signs win: if they say merge here, merge there. General information, not legal advice. Other states differ: check yours. #zippermerge #latemerge #drivingtips #roadrage #newdriver

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Monday 09 November 2026 22:00:00 GMT