i hate bot, but ill usually play Lucian if i get stuck with adc and want to win. not because he's op, but because he's fun and I've played him the most out of any adc.
that said, i would say he is fantastically average. His lane is somewhat safe (relative to other adcs). Vayne and trist are safer, (basically 2x escapes whereas Lucian only has 1.5 (.5 is generous ... the movement sped on W isn't so great if you need to escape)...
however, his lane is somewhat strong imo. I would say it's strong, but it's a damn shame Vayne, who has become such a common pick, can so easily avoid his Q. If you can bait her tumble, or just wait for her to waste it, his Q is great. But usually, a good vayne would just save it for you to Q. But, if you can land Q consistently, he can win most match ups.
The other thing is, he would be stronger, but since it's 2v2, a lot of supports can compensate for a weak adc. Alistar for example would make vayne basically unkillable in a 2v2 scenario. Not that they will kill you, but they can shrug off most all ins and out scale with vayne. If it were 1v1, I think Lucian would be a dirty adc, but typically a good support can carry their adc through lane if need be. Still, his mid game is nice, and his late game is ok. With good peelers and farm, he can totally carry late game fights. It's just not as flashy as say vayne or trist, but with some CDR he can proc his passive enough and get to the killing.
so, basicaly tl;dr imo: his lane is at worst average...he can bully if you are skilled and aggressive. He doesn't scale amazingly, but he also doesn't fall off too hard late game. Solo Q i like him, because he is a somewhat self-reliant adc.