Space is very, very empty even in the solar system. Interstellar space is far emptier. If I were inclined to go on such a trip I would be happy to launch tomorrow without a second thought. Average daily life on earth carries hugely bigger risks than the infinitesimal chance of a collision in deep space.
There are many obstacles such as space pigeons that you cannot avoid.
https://www.youtube.com/watch?v=xPCZtrac-Ss