The Alaskan Way Viaduct’s days are numbered, with its decommission date fast approaching—the viaduct will close to cars forever on January 11. That starts a three-week process of switching State Route 99 connections through a brand-new tunnel. Once that process is complete, the viaduct will be demolished.

But the viaduct wasn’t always a crumbling, earthquake-vulnerable death trap. Back in the middle of the last century, it was a brand-new, long-awaited solution to increased city congestion. City officials started floating at least a similar idea as early as 1916, although discussions began in earnest during the 1930s—especially as the Aurora Bridge started piping more cars into downtown.

The viaduct is leaving the world in segments (including one that’s already gone), but it came to be in segments, too. Construction began in 1950, split up into a few segments across five contracts. The first grand opening was in 1953, running from Elliott Avenue to First Avenue S. The Battery Street Tunnel, then the Battery Street Subway, opened the next year, connecting the roadway to Aurora Avenue. The last stretch to open was the southern extension to Holgate in 1959—also the first stretch of the viaduct to go, torn down in 2011.

We’ve rounded up some photos from the Seattle Municipal Archives throughout the highway’s birth decade, from initial construction to final unveiling.