Why are so many poems written on trains?
Tomorrow is National Poetry Day - and one of the many publications marking the event is a collection of verse celebrating rail travel.
To find out why the rumbling motion of a cross-country journey gets the creative juices flowing, I took a slow train from Marylebone Station in London, to Aylesbury in Buckinghamshire.
The poet Don Paterson explained that train travel is "a metaphor for your life... the driver as god or your superego... and you can change train in the way that you can sometimes switch face."
Have a listen to my report, which was first broadcast on the Today programme, on Wednesday, 2 October, using the player on the right.