Using advanced image capturing and AI data-processing technology, scientists from Ellipsis Earth worked with environmental charity Hubbub to create a detailed map of the locations and types of litter dropped across the roads of Cardiff and South Wales. Vehicle cameras were used to survey 12 roads across the highway network in and around the city, including motorway, A-roads and B-roads.
A total of 146,662 items were detected on Cardiff’s roads, an average of a piece of litter every 1.22 metres, with higher littering levels evident on Fridays, Saturdays and Sundays. The data revealed relatively low levels of litter on motorways (an item every 23 metres) compared to twice as much on A-roads and five times as much litter on B-roads.
The data showed that litter accumulates where vehicles drive at slower speed, such as junctions, slip roads and roundabouts, and after the exit points of fast-food outlets at junctions. It also showed that 68% of litter in the region is found on roadside verges and junctions, with junctions showing 25 times higher rates of littering than open road verges, particularly on A roads.
The survey also found that litterisdropped every 3 seconds on the roads of Cardiff which creates a significant burden on local services and impacts on local people and our wildlife too. Furthermore,paper, cigarette butts and plastic fragments, often broken down from food and drink litter, were the top three types of roadside litter.1 Half of all litter in Cardiff roadside is paper-based (napkins, receipts and paper packaging).
In addition, data showed that Cardiff itself is not a major sink or source of litter, rather that litter flows evenly through the city, in a predominantly easterly direction.
After the initial survey, Hubbub tested litter-busting interventions, in partnership with various key organisations: Welsh Government, Cardiff City Council, Vale of Glamorgan Council, Keep Wales Tidy, Welcome Break and Fidum Property Management.
Supported by a radio and social media campaign, new eye-catching signage on bins, signs and signage were rolled out, encouraging road users to ‘Keep it ‘til you bin it’ and to do a 2-minute tidy of their cars. Interventions included signs around Culverhouse Cross roundabout, bins and signs in Brooklands Retail Park and Welcome Break Services at J34 on M4, and new road signs around Junctions 33 and 36 on M4.
A second survey measuring changes in litter levels then showed the impact of the interventions. It found that:
· The combination of billboards, signage and bins together significantly reduces littering at motorway services. Litter reduced by 23% in the Welcome Break Service area where multiple bins and signs were located
· The presence of multiple signage at junctions reduces the litter accumulation rate on slip roads
· Isolated signage has limited overall impact on roadside littering in Cardiff
Gavin Ellis, Co-founder and Director of Hubbub said: “This is the first time AI has been used to map out roadside litter and the learnings we can take from this work in Cardiff can actually be applied to areas across the UK.
“The data shows we need to make it easy for drivers to bin rubbish, provide bins where drivers stop, and ensure they are visible and easy to access. It’s also important we encourage them to bin rubbish before getting on the road again. We strongly believe that collaboration between highway agencies, councils, and businesses is key to tackling roadside litter and that targeting litter hotspots with combined bins and signs save time and money. We look forward to sharing the learnings from this study more widely to help ensure the effort is being targeted in the right places.”
A Welsh Government spokesperson said: “Roadside litter is not just unsightly, it is costly and dangerous to remove. We are pleased to be involved in this campaign which is a positive step towards tackling roadside litter in Wales. The litter survey provides us with fascinating insight into where litter is being dropped and when across the region, with robust data clearly identifying those locations with highest litter levels, such as junctions and slip roads. This will help us and all those working to tackle roadside litter to focus their efforts and introduce the right measures in the right places.”
Pam Bacon, Regional Manager at Keep Wales Tidy said: “It has been fantastic to be part of this groundbreaking project. Roadside litter is a blight on our beautiful country; it is often the first thing visitors see when arriving in Wales and has a significant impact on our environment and wildlife.
“Thanks to AI, we have gained valuable insights into roadside litter types and locations, as well as the effectiveness of a number of intervention options. We look forward to working with partners in the future to apply the lessons learned.”
For more information visit  www.hubbub.org.uk/Tidy-Roadsides
