Environment Minister Stephen Dawson said the State's $185,000 Regional Roadside Litter Prevention Project (Roadside Litter Project) had successfully changed motorists' behaviour, reducing litter by an average of 55 per cent at trial sites on the Brand, Great Eastern and Forrest highways.
It also highlighted the importance of the McGowan Labor Government's Container Deposit Scheme in dealing with drink containers, one of the most commonly seen litter types. The scheme is set to begin in early 2019 and will offer a 10 cent refund for eligible drink containers.
As part of the Roadside Litter Project, big anti-litter signs were installed along the highways and 300,000 free car litter bags were made available at service stations and roadhouses from August to December last year - encouraging motorists to do the right thing and dispose of their rubbish correctly.
Litter volumes at trial sites along the Brand and Forrest highways reduced by 49 and 60 per cent respectively, and by 70 per cent at the Great Eastern Highway site.
More than 7,200 items of litter - 1,496 litres in volume, which could fill a backyard water tank - was collected from just four kilometres of highway.
Plastic and glass bottles, drink cartons and fast food wrappers accounted for 69 per cent of all litter collected.
Comments attributed to Environment Minister Stephen Dawson:
"On World Environment Day today, it's important to remember that littering not only makes our highways untidy, but it also harms the environment - putting wildlife at risk.
"The Regional Roadside Litter Prevention Project has shown, that by offering free car litter bags and a reminder to not litter, we can change motorist behaviour.
"Last year, Main Roads WA spent $6 million collecting roadside litter and debris - funding that could be diverted to other essential State Government services.
"This project is a great step towards our aim of reducing litter - ahead of the launch of our new Container Deposit Scheme in early 2019, which aims to reduce beverage container litter and boost our