That's a good question. I would think that modern ships should scream "collision course ahead" with light, sounds, etc. However, psychologically, maybe it's believed that this would make people even _more_ complacent? I don't know, just speculating. Never the less, the captain should never allow his sailors to think, "we're almost there, we're in friendly waters, we can relax". No, always on alert. It's unforgivable.