Jarrett Walker has been designing bus networks for thirty years. From his consulting practice in Portland, Oregon, he’s built a specialism in helping cash-strapped local authorities optimise their networks through his business Jarrett Walker Associates.

And you can’t optimise if you don’t know what public transport is actually for and how you’re measuring whether or not it’s achieving those goals.

Eventually he’d done so much thinking on this topic that he wrote it all down in his book Human Transit.

In our conversation, he talks me through why it’s important to understand whether a transport network is seeking to optimise for coverage or patronage and how ‘access analysis’ can provide everyone with their own personal measure of public transport freedom.

Birmingham was the first city I lived in as a proper ‘grown-up’ and it was metamorphosing before my eyes.

Previously famous as Britain’s ‘car city’, it ripped up its inner ring road the year I arrived.

Today, the city centre is unrecognisable: spacious, walkable and with a brand new tram route snaking past brand new buildings.

Anne Shaw has been involved in this transformation since she first moved to Birmingham in 1991 to take up a job as a drainage engineer.

Today she’s Executive Director of Transport for the West Midlands, and she tells me just how this extraordinary change has been achieved.

One of the world’s most expensive railways is being built, but will it actually be useful? The new trains won’t fit into the existing station in Manchester and the railway north of Birmingham has insufficient capacity.

Someone who thinks they know how to fix the mess is Chris Gibb who, amongst many other roles, used to run Virgin West Coast, the very railway that HS2 is designed to replicate.

He describes his plan on this week’s episode.