It's definitely improved noticeably since '16, when I moved out here. Which Washington Street? I live by North Station, and biking to the Charles River Path is a little scary, but once you're on the path, it's pretty easy to get to most of Back Bay/Fenway without too much of the way shared with traffic. There are still big gaps, but the number of grade separated paths in the West/North End, at least is heartening.
Seaport could be much better if enforcement was there at intersections. I've tried to use 311 to report drivers sitting in their cars at them.