Why we're stuck in traffic: An answer from November 1966

Seattle traffic, as you know, has become monstrous. Delays on regional freeways doubled between 2010 and 2015, according to the Puget Sound Regional Council. Why have our highways failed us so? A 50-year-old document provides one answer. This and other documents unearthed at the National Archives in Seattle show that we are currently driving highways built when people could not imagine this pumped-up, Boeing+Microsoft+Amazon version of Seattle. The people who designed our highways fought for the driver of the future, but the future they envisioned was 1975.

Back then, in the 1960s, I-5 had just been built. Roughly 107,000 cars were driving over the Ship Canal Bridge on the interstate. That’s kicked up to 205,000 cars, according to the state. And that narrow span from I-5 to the 520 bridge? That sees 75,000 cars on a weekday, according to the Seattle Department of Transportation – well beyond 35,400 cars in the 1960s. More insights from documents found at the National Archives in Seattle: It looks like someone on the team building the highways kept this old map, updating it after the dreamed-up highways finally opened. (Yes, that does appear to be colored pencil.)

It's a reminder that Seattle's highway system was designed in the 1950s, when office work was harder and slower, and a simple illustration wasn't simple at all. One highway not getting the colored pencil treatment: the doomed Empire Expressway, also known as the R.H. Thompson Expressway. This second, north-south highway faced heavy opposition and was killed in 1970. This is one of many blueprints of interchanges found in the archives. This document contains the first glimpse of engineers noting future problems. In pencil, one engineer indicates, "100 vehicles per hour will have to turn left from this lane!!!" which must be a problem because of all the exclamation points used. This is not the interchange as it is now. Perhaps that engineer got his point across.

Traffic counts at this intersection seem tiny now by comparison. There was a time when cars from Wallingford, Fremont and Ballard were not expected to surge toward I-5. (Ha!) Today, 22,200 cars from northwest Seattle crawl onto that bottleneck that is 45th & I-5, according to the Seattle Department of Transportation. Traffic counts listed on this ancient sheet now look tiny compared to today. With pencil and loose-leaf paper, an engineer calculates the potential for slowdowns because of weaving between these two highway ramps: Union and Howell in Seattle's downtown. "Washington office worried about two nosings in quick sequence..." the engineer notes, using the Mad Men-era term for merging.

I-5 is an interesting highway for weaves (nosings) because the freeway ramps are on the left and right sides of the freeway throughout Seattle. This forces cars to slow and jostle. No lane appears immune, so the fast lane isn't really the fast lane. And the slow lane is only marginally better. According to this yellow scrap of paper, a man, surname Barron, met up with three other men, Bogart, Bentley and Bell. It was Aug. 16, 1965. The meeting was impromptu. There was a sense of urgency. This Creek Interchange on I-405, wherever that was: It had to be dealt with. Misters B, B, B and B knew they weren't interested in a "bastard" style of interchange, whatever that was. Bogart got to the point. It had to be simple diamond, he said, according to record. Nothing else would do. B, B and B agreed.