There are a bunch of wider streets, like 28th Ave. NW, 20th Ave NW. I’m pretty sure they were for old street car lines, with the tracks down the center and roadway on each side. Old Ballard was it’s own city and had it’s own street grid.
In some places you can see the old cement roadways on each side and the center is filled in with asphalt where the tracks would have been. In some places you can see where the tracks took a corner, like at the intersection of NW 67 and 20 NW. or at NW 67 and 28NW.
The second and third pdfs show the 59th street line. I remember a few years ago when SDOT installed a traffic circle at 64th and 34th, when they dug up part of 64th I saw the old rail ties in the dirt! Very interesting.