http://www.priceoftravel.com/595/pub...ldwide-cities/

So, it looks like they've overstated the minimum London fare, and
included peak fares for routes from the centre to places well outside
London when calculating the maximum fare. I wonder how wide ranging an
area the fares they quote for other cities are?

For Toronto...
For the New York subway...
For Paris...
For San Francisco...

Thanks for the info -- do the fares quoted look right for these cities?

A further issue that can make these comparisons misleading is that some
cities offer reduced fares if you buy, say, 5 tickets at a time -- what
the French call a carnet -- and others don't. I think the carnet fare
is the correct comparison since most people who don't use a pass (season
ticket) will pay that amount. They have chosen to show the single-trip
fares. If they had shown the carnet-type fares, the numbers for New York,
Toronto, and Paris would have been lower by amounts (using today's fares
in early 2013) varying from 7% to 21%.

And do they, like London, have different off-peak fares?

In all four cases, not that I am aware of.
--
Mark Brader "Well, it's not in MY interest -- and I represent
Toronto the public, so it's not in the public interest!"
-- Jim Hacker, "Yes, Minister" (Lynn & Jay)

My text in this article is in the public domain.