Does this suggest a serious danger to any hypothetical interstellar ship? If the density of such kilometer-scale objects is such that disk of our solar system intercepts them by the dozen, there is one fuck of a lot more solid matter drifting through interstellar space than I have ever seen suggested. Sure, as Douglas Adams said, "Space is big. Really big," but still: if you imagine traveling even a very modest fraction of C, this begins to make the Millenium Falcon in the asteroid field[1] look like real science.
[1] https://youtu.be/c8deRYotdng?t=133