A new smartphone app is tackling the problem of abandoned supermarket trolleys by allowing the public to report their exact location for collection.
The free Trolleywise app for Apple and Android devices lets users send photos of trolleys, triggering a GPS system that alerts a national collection service.
One of a fleet of 47 vans can be sent to the location within 24 hours to recover the trolley and return it to the supermarket, saving local authorities and retailers millions of pounds in costs and charges each year.
The service is backed by Sainsbury's and Asda, but even non-subscribing stores will have their trolleys retrieved for collection from the nearest depot.
According to Trolleywise, a retrieval service paid for by retailers, up to 400,000 of the more than two million trolleys in circulation go missing every year.
Many end up dumped in canals or in and around city centres.
Trolleywise has pledged to make a donation to the Trees for Cities charity for every trolley it collects, with the aim of raising enough money to plant at least 2,000 new trees in urban areas each year.
Trolleywise managing director Tony Barber said: "We have made a substantial impact in managing the abandoned trolley challenge, with Trolleywise retrieving almost one million trolleys since 2012.
"However, we want to eliminate the problem altogether and return pride to our local communities. The app makes it very easy for people to report trolleys quickly and accurately. By swapping abandoned trolleys for trees, we want to make a positive impact on communities."
Trees for Cities chief executive Sharon Johnson said: "We often come across abandoned trolleys as part of our tree-planting work in local communities. We hear from our volunteers that there is confusion about how to report them and whose responsibility it is to pick them up. As a result, we're delighted that Trolleywise has launched this app to make the process so simple."
Environment Minister Lord de Mauley said: "Abandoned shopping trolleys are not only unsightly but have a real impact on the local environment.
"This innovative app will give shoppers and residents the chance to take swift action to tackle the thousands of shopping trolleys scattered around our streets or thrown in rivers and canals. It will play an important role in making our neighbourhoods more pleasant places to live."
A spokeswoman for Tesco, which will be using the service from this week, said: "Our colleagues work really hard to collect and secure Tesco trolleys every night, with many of our customers helping us keep our trolleys tidy too. For those few trolleys that do go astray, we know how frustrating it can be for local communities.
"It's great that the Trolleywise app will make it easy for people to alert us to abandoned trolleys, so we can pick them up quickly and play our part in keeping communities tidy."