Christian Wolmar

by the underworld period was commuting.

And commuting was largely on kind of rather slow suburban trains that people were packed into like sardines.

It wasn't a great experience.

There was a big debate in the interwar period where some rail industry figures really wanted to stick with steam, and they tried to improve steam.

You have, at the same time, in Germany, kind of fast diesel trains being developed.

And in America, you have these amazing streamliner diesel expresses, which are seen as the future.

Whereas more forward-looking people begin to realize that diesels and, of course, the best form of traction, electricity, begin to dominate.

their survival and the fact they're thriving in the 21st century thanks to the huge advantage that commuter railways, high-speed railways, heavy freight railways, and sometimes even local areas have over other means of transport and the fact that they've won through.

So it's obviously a developing story and who knows where the railways will be in 50 years' time.

But I suspect that they won't be very different from now.

They will be faster.

They will be

probably more efficient, but I suspect they will be the mainstay of many countries' transport systems.

China's built 30,000 miles of high-speed line in the space of less than 20 years.

Japan runs 270 trains a day between Tokyo and Osaka, each with about 800 people in them.

The metro systems are popping up in all sorts of places you wouldn't imagine.

It's ubiquitous.

If you could bring Stevenson back from the dead, I think even he would be surprised at how well his invention has done.

I think he might have thought he'll take a few people between Liverpool and Manchester and there might be trains a bit around.

But I don't think that he could have envisaged that.