Britain From Above 1. 24 Hour Britain (7 of 28)

Britain From Above

So whereas on the Continent they've got double-deck trains, it's very difficult, and expensive to do that here.
If we want to lengthen our trains, you have to lengthen the platforms.
And we've been tinkering at the edges, trying to adapt that Victorian legacy to 21st-century commuting patterns and demands.
If our railway system has been half-strangled by history, what about the streets?
Because we're still trying to drive in our major cities - this is London - on a little network of old roads and alleyways which were put there for pedestrians or people on horseback, and yet we still have to move through them.
And, my friends, it is not easy and it rarely makes us happy.

By using satellite technology, we can look down and see how this entire network of city streets is being pushed to the edge of capacity.
We've got hold of the GPS traces of 380 London tsxis, recorded over the course of a single day.
In the dark hours before dawn, the streets subside to just a few flickering traces - glow worms taking the last of the night's revellers back home.
But then, from seven o'clock, we begin to see fleets of vehicles flock towards the centre, following the major arteries - east, west, north and south.
And when our tsxis hit the centre, the city begins to light up with flickering movement.
Major thoroughfares grow ever hotter with activity.
Then, as they become saturated, the tsxis start to spill out into the back streets, searching out any clear route they can find.