Hate how busy Manchester gets on match days? You'd better get used to it...

Mancunians are very well accustomed to the impact that match days have on the transport network, with loaded trams, trains and buses - and gridlock often witnessed on all city centre roads.

Scenes on Deansgate when United played Juventus on October 23rd

The recent roadworks across the city centre have laid bare how ill-prepared Manchester is for a population explosion.

And yet, a population explosion is already underway in the city - and is set to continue for a number of years. UrbInfo's research shows that, in 2018 so far, 2,338 homes have completed construction across the area covering Manchester city centre, Salford, Salford Quays and Trafford. A further 1,952 are due to complete before the year is out, while 2019/20 will see a further 11,638 homes complete in the same area (at least). By 2021, there could be as many 30,000 additional homes across the Manchester city centre, Salford, Salford Quays, Hulme and Old Trafford areas.

The area that UrbInfo's research covers. There could be many as 30,000 new homes delivered here over the next three years. Salford wards in red, Trafford wards in green, Manchester wards in yellow

But how does this translate into actual people?

In Manchester, the average number of people living per household is 2.3. For Salford it's 2.2, and for Trafford it's 2.4. For the whole of Greater Manchester, it's 2.3.

This helps us form a rough projection of how the city's development boom will play out in population terms over the coming years.

Of the 2,338 homes which have completed across the city so far in 2018, 690 have been in the ward covering Ancoats & Beswick, 398 in Clifford ward (Trafford), 11 in the Deansgate ward of the city centre, 138 in Hulme, 60 in Longford ward (Trafford), 759 in Salford's Ordsall ward and 282 in the Piccadilly ward of the city centre.

Assuming all of these schemes are full, there may now be as many as 5,347 extra people living in the city as there were in January. 1,099 of these are living in Trafford borough, 1,670 in Salford and 2,578 in Manchester.

Going forward, nearly 30,000 more homes and apartments are due to fill up the cityscape by 2021. Two-thirds of them are already on-site, witnessed by the forest of cranes currently puncturing the skies above the city. The majority of these apartments are being built in the city centre, as the graph below shows, but thousands are also being built in surrounding areas such as Salford Quays (included in Ordsall), Hulme, Old Trafford, Cheetham, Rusholme and Moss Side.

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Making some very rough assumptions, we can use the above to calculate (approximately) what kind of population increases we may start to see in each area of Manchester by 2021. The following graph assumes that all new homes get completed and filled. For Trafford wards (Clifford, Gorse Hill and Longford), we have projected 2.4 people per household. For Salford wards (Ordsall, Irwell Riverside, Broughton), we have projected 2.2 people per household and for Manchester wards we have assumed 2.3 people per household.

In total, Manchester could see a population explosion of about 67,190 people. Again, it's important to iterate that this number assumes that all new homes will get built and will be filled.

To see what impact dropping an extra 67,000 people into Manchester does to the city's infrastructure, you need only look at what happens when either United or City play at home.

Statista suggests that Manchester United's average match attendance is about 75,000. For City, over 54,000 attended matches on average in 2016-17.

What happens when you drop an extra 60-70,000 people into Manchester all at once?

It would be unfair to suggest that these scenes will become every day by the year 2021. For a start, these extra 67,000 people will not be arriving all at once as they do for home matches. They will gradually be integrated into the city over the next three years as new developments complete. Infrastructure upgrades will occur in time: such as the MSIRR improvements currently underway on the Ring Road, which will help deal with congestion. New infrastructure such as Chris Boardman's Beelines cycle network will be more advanced by 2021 so a lot of these extra people may cycle, rather than clog up the roads with cars.

Additionally, more than half of the new apartments being built are in the city centre, in locations which allow residents to walk everywhere they need to go. Many new apartment developments have restricted parking, making it very difficult for residents to own a car. Of the 12,731 homes being built outside the city centre, 7,157 of them are being built within a four-minute walk of a Metrolink station. The rest are near either high-frequency train stations or on frequent bus routes (or both!)

And although 2.4 people live per household in Trafford currently, 2.3 for Manchester and 2.2 for Salford (which is what we've based our population projections on) some of these new homes may contain much less than that - many will be single occupant residents. The impact on actual population may be much less steep. It's also possible that not all of the apartments proposed will actually be built.

But one thing is clear: Manchester is getting busier, and that's only set to continue. Resident population is only one side of the coin. There are also many millions more square feet of office space under construction in the city, which will enable thousands more city centre workers over the coming years. There are over 5,700 student bedspaces proposed for the city on top of the number of apartments, and match days, conferences, arena shows are all set to continue.

And it isn't all bad: these extra residents, workers and visitors will provide more footfall for the city's shops, bars and restaurants. They will stimulate the economy and the buzz of having so many people in such close proximity is what propels major cities all around the world.

Download all data used in this article.