A couple of weeks back, the Greater London Authority released the excitingly-named London Infrastructure Plan 2050: a suite of documents proposing everything from a new orbital railway line to better flood defences.

The plan is largely a response to the fact the capital’s population is growing at the fastest rate in decades. At some point in the very near future (6th January 2015, the GLA estimates) London will breach the previous population record of 8.6m that it set in 1939. And that growth is not slowing down. By the middle of the century, it’s likely to increase by nearly a third to hit 11.3m; it could get as high as 13.4m.

This, as you can imagine, that will put quite a strain on the city’s infrastructure. In case you haven’t had the chance to read the entire plan yourself, here are some salient points:

1. London could have high-speed trains to Stuttgart, Strasbourg and Geneva

One of the plan’s transport priorities is extending the rail links into Europe. This would take some pressure off airports, reduce freight traffic on the motorways and, best of all, make for a wider range of city breaks. The proposed network could look like this:

They’re even thinking about installing an “additional cross-channel rail tunnel” to accommodate more international rail journeys. This plan, though, isn’t included in the cost estimates.

2. Where the extra Londoners live will depend on where the infrastructure goes

The report includes some nifty visualisations which shows how different policies would affect the city’s population density. If it continues with its current policies, by 2050, London’s population density could look like this:

Basically that’s a lot of people in the centre and along the river, but far fewer as you head out of town.

But different options are also on the table. One is to increase density in London’s various “town centres”. If that happens, the report’s authors reckon London’s population would look like this:

Suddenly, that’s lots more people in far flung places like Coulsdon, Upminster, and Feltham. That would mean that any growth in population happens in areas that already have decent shops, facilities and transport inks.

3. London needs faster broadband

Broadband, or “High speed connectivity”, actually gets a whole supporting document to itself (in city planning circles, that’s a pretty big deal). The government is aiming for 99 per cent of the population to have access to “superfast” connections, which can be as fast as 300Mbps, by 2018. At the moment, the average British broadband connection runs at just 12 Mbps.

But the areas with the darker grey dots on this map have speeds of just 2 Mbps connectivity:

In other words, much of the capital is stuck in a broadband blind spots.

If the GLA gets its way, a city-wide Connectivity Advisory Group would be given the job of monitoring the capital’s broadband speeds and trying to plug the gaps. One possible solution is to re-use the ducts that borough councils use for CCTV systems as a housing for broadband wiring; another is creating communications hubs for communities to use – like New York’s plans for Wi-Fi phone boxes.

4. The money doesn’t have to come from Westminster

“Throughout these documents runs a golden thread,” Boris Johnson says in his introduction to the planning document. “London government needs more financial powers to invest in London’s infrastructure and support its growth.”

That “golden thread” is surprisingly literal. Delivering this plan will take a lot of money: £1.3 trillion, according to Arup, the engineering consultancy that worked on the plan. Based on the city’s current population of 8.4m, that’s a cool £154,762 per head.

Asking for a sum of this sort isn’t likely to win the capital many friends in places like Birmingham and Leeds, that are crying out for public investment themselves. But, as Boris says, this money doesn't have to come from the national government. The report highlights the work of the London Finance Commission, which called on the government to devolve property taxes to the city authorities; it wants the city to have greater powers to borrow, too.

In this way, London would be able to finance its own infrastructure needs, without needing to compete for cash with the rest of the country. (While we're at it, why not devolve powers to the country's other city regions, too?)

5. Someone didn’t check the transport document’s back page.

Well, you can’t plan everything.