Massive thanks to co-author Caitlin and staff at all six transport authorities for their insights. Also to previous Centre for Cities' colleagues for laying the foundation for the modelling that was the backbone of this analysis.

You can read a summary of our work in this blog below:

For the mayors - a big prize is good news! This means sticking to their plans already in motion to make public transport function better.

This will still require some hard policy choices. But the tools will be on the table from early next year. Next step is to go for it 🚌

Back to the prize. Let's translate it to cold hard cash. By increasing effective city size, we estimate £17 billion in additional economic output through 'agglomeration' productivity gains.

So the prize is big. To win it, government must continue to support mayors improving their local transport.

It's not just about improving public transport though, especially for mayors with sustainable travel goals.

Impacts will be limited (in the Yorkshire city regions, cut in half), if no changes are made on residents' relative ease of driving.

You could also get similar connectivity impacts through densifying cities - Newcastle is a good example here.

But again integration complements this - better transport makes these projects more viable, and public land assembly easier.

Integration makes other levers to increase citys' effective size easier to pull.

Connectivity impacts of West Yorkshire Metro Phase 1 plans (on best current information) would be trebled if they happened within an integrated network.

Fixing the fundamentals unlocks these bigger projects.

But mayors should not stop at one. Steps are complementary. Doing one multiplies the impact of the next.

As this map of Liverpool shows. Increasing frequencies and modal integration together has double the impact of each on its own - see the light blue areas only unlocked with both.

Different steps work best in different places.

For Leeds (and other smaller city regions), filling in bus frequencies is the biggest first step.

For Manchester, it is better use of existing tram and train services, linking to already frequent bus routes

Sheffield shows you how these steps work together in practice. Better bus frequencies fill in under-served gaps, modal integration allows train and tram stops to reach further, and faster journeys mean existing services can stretch out the network's area.

Think of this this way. This is like the UK having an extra big city - 1.5 times the size of Leeds - with all residents well connected to some of the biggest concentrations of economic opportunities in the country.

All by using existing public transport 'better'.

The size of the prize. We estimate that 1.2 million more people across these six cities would be better connected to their city centres under integrated public transport within a reasonable journey. That's 4.3 million total, a 40% increase. And it would bring them much closer to European standards.

So we modelled this. Tracking thousands of live bus locations on weekday mornings, and matching with trains and timetables, we wanted to see what connectivity looked like in each place, and how the three steps above could expand that.

Months of staring at (and dreaming about) buses lead to...

The powers unlock three big steps mayors can take to improve their networks: increasing frequencies and reducing journey times on key bus routes, and better linking up bus, tram, and train routes. All increase city centre connectivity, deepening labour markets and expanding access to opportunity.

This is about fixing the 'nuts and bolts' of public transport, making a network function efficiently as one system.

For England's 6 largest cities outside London, the policy pipeline will give them unprecedented powers to better connect residents to economic opportunities through integration.

No, unfortunately beyond the scope of this project, but something I definitely want to explore in the future!

Thanks Andrew!