It's been a few years since I've been to Seattle, but other than trails along the bay I don't recall biking within the city itself feeling safe. Were there many protected bike lanes?
* There are frequent car crossings at blind alleys and driveways, often every 20-30 feet.
* Many are "protected" by flexible posts that are easily driven over.
* When protected bike lanes run next to roads, drivers often turn across them at intersections without looking.
I generated the map with Overpass Turbo: <https://overpass-turbo.eu/s/1mT6>. To make it render nicely, check "Don't display small features as POIs" under settings. If you want to try it for a different city, drag/zoom it into view and hit "Run".