Crossrail 2 VS Chelsea - Hackney Line

[freetoview33]

I think for the reason that everyone would pile onto the Victoria line! It's far better and quicker to the West End, and indeed Euston/KXSP from there than the Northern crawling via Kennington.

But yes once they're both opened and Victoria & Vauxhall have relief, a southern extension to at least Herne Hill makes sense. Although taking it down to Streatham and axing a few of the many buses up Brixton Hill must be a contender too.

Obviously it would have to be after Crossrail 2!