I was horrified to read that Boris Johnson has asked TfL to work up plans for a £30bn ring road tunnelled under London.

Apart from the traffic generation and extra air pollution it would cause £30bn is a colossal amount of money.

We could build roughly 6 complete new underground lines in London for this sum. Such a huge expansion in tube lines would bring huge benefit to all Londoners not just the tiny minority that drive in central London.

Or we could build 300 new tram lines across London. A revolution in public transport.

Or we could make every street and road in London utterly cycle friendly and still have many billions of pounds left over.

How would you solve London transport problems with £30bn?