"The London Underground celebrates its much-publicised 150th birthday this
week. The system is the oldest in the world – nearly four decades older
than any of the world’s other large metro systems – and has been lauded as
a model of public infrastructure investment. But how does it measure up to
its younger imitators?

In passenger and station numbers, it’s dwarfed by some of the new kids on
the block."



Also remember, away from the centre, large parts of the Underground
were originally main line railways.

Indeed, so were some in the centre.

The amount of actual new build Underground is quite small.

How does that compare to elsewhere did other cities incorporate
existing main lines into their Metro systems?

I'm sure the answer to that is yes but wonder what would be the
largest genuine Metro system, all built from day one as Metro.