This article follows on from our recent piece on the positive environmental impacts parcel deliveries by drone would have on the UK. In that article, we found that if 50% of parcels in the UK were delivered by drones, this would be the impact:
- 315,000 drones would be required
- 1 billion road miles would be saved each year
- There would be 53,000 fewer delivery vehicles on the road
- A 250,000 Tonne reduction in CO2 emissions
Given the intriguing feedback we received to these figures, and also in response to this article from The Conversation, we decided to analyse an angle sometimes cited as an area of concern when considering how to unlock this technology and future.
In this article, we will be looking at the potential noise impacts of drones delivering parcels.
The positive environmental impacts of using drones to deliver parcels – for example, by reducing our UK C02 output by 250,000 tonnes per year – may not be an overly visual concept.
However, images of skies potentially ‘swarming‘ and buzzing with drones in a somewhat biblical fashion appear to have captured the imagination of the public and indeed, some areas of the media, in a much more vivid fashion.
So are these prophecies of ‘drone-doom’ realistic? Just how much ‘sky’ does the UK have, relative to its population? What would the noise impact be on an average person when it comes to drone deliveries?
How do we work this out?
To figure out any potential impact, we had to take a step back and look at the makeup of the whole of the UK. How much of the UK is built upon and densely populated, and how much is rural and sparsely populated?
Well, according to research by the University of Sheffield, it is suggested that “less than 6% of the UK is urban”. To help to visualise this, imagine a standard football pitch. The percentage built upon would be one of the corner flag arcs – a surprisingly small amount.
This leaves much of the UK open to drone ‘transit corridors’, which could be in carefully mapped out and controlled airspace, far away from areas where any noise impact could be an issue.
In fact, the consequences of drones being in these areas would be virtually nil. After all, if a tree falls in the forest and no one is there to hear it… you know the rest.
What about urban areas?
Of course, the very nature of parcel deliveries means that they almost certainly need to enter more densely populated areas. This would involve leaving the previously mentioned ‘transit corridors’ and entering areas where people potentially live and work.
So we ran the figures to take into account the population density and impact specifically on the UK’s urban areas, too.
The average population density per kilometre squared, in the UK’s urban areas, is 3500 people. That gives each person in the UK in urban areas 286 metres of space – even if sometimes it doesn’t feel like it!
Now, some assumptions are going to be needed here as this modelling has never actually been done. So please bear with us.
These drones will of course be flying at different distances from people, depending on the phase of flight and their destination. We’ve categorised a couple of example ‘average’ distances of the drone from people as follows:
- High Impact: The drone is within 50m of people. Noise at this distance is quite pronounced – the drone is definitely noticeable. Average time in this phase is 5 minutes.
- Medium Impact: The drone is within 100m. Noise at this distance is negligable – similar to a car driving past. Average time in this phase is 10 minutes.
- Low Impact: 200m from people. At this distance, the noise of the drone is not noticable or visible. Average time in this phase is 15 minutes.
With those figures in mind, coupled with the previous analysis of population density in urban areas of the UK, lets take a look at the possible impacts on an average person.
If 50% of parcels currently delivered in these areas were done so by drone (a figure you may remember from our previous article, in order to keep things consistent)… then only two parcels per day would be delivered in an area of high impact.
The majority of a drone’s delivery routine would take place in the medium and low impact areas – locations where a drone’s presence is usually barely heard or not heard at all by people.
Of course, in suburban and rural areas, this effect would be even lower.
Whilst it is easy to get drawn into an imaginary world where buzzing drones fill the skies, in reality, there really is an awful lot of sky.
Impacts of drone noise on an average person wouldn’t be zero, but would be low – even in the relatively densely populated UK. In our view, the impact is acceptable and in most cases, mitigable. The abundant positives of parcel deliveries by drone by far outweigh any potential negative affect caused by noise pollution.
Think back to a time when passenger airlines first started flying their planes overhead – people would have no doubt looked up, intrigued by this new phenomenon.
Fast forward a few years and the novelty had worn off. People notice less and less what is always there.
Drones are increasingly set to become a part of everyday life. In the future world we have talked about, an average person will notice just two drones a day. Is that excessive?
Sure, you can design drones with ‘perception-influenced engineering’ in mind, to make them quieter or slightly different acoustically. But will noise from drones fade into the background regardless, just like the noise from passenger planes did?
Only time will tell.