Visitors to the North Coast 500 (NC500) are being urged to borrow cups from cafes on the route to “reduce litter” from single-use drinks containers.
The Highland Cup Movement allows customers to take a reusable cup for free at one outlet and return it to one of dozens of others close to the route.
They have two weeks to return the cup and lid to avoid being charged £4.
It comes as the Scottish government publishes its litter strategy which pledges more support for targeted interventions like this.
In the next year it also plans to introduce fines on the registered keepers of vehicles from which littering offences are committed.
Tougher penalties are also planned with the fine for flytipping increasing from £200 to £500, while exploring the option or raising it further to £1,000.
People who want to take part in the voluntary cup movement scheme have to register their details on an app which they then use to scan a QR code on the lid.
So far, 25 businesses have signed up from Applecross to Castle of Mey near Thurso.
Laura Thompson owns Slaughterhouse Coffee which sits by the slipway for the small car ferry running between Cromarty and Nigg.
She acknowledges that single-use coffee cups are a big problem for the hospitality sector and that they need to promote alternatives to customers.
Laura said: “Some are really keen. I think those are the ones that are already aware of how much of an issue disposable cups are. Others, I think it’ll take a bit more time.”
About 200 million disposable coffee cups are used each year in Scotland alone, according to the Scottish government.
They have been planning to introduce a levy of around 25p to use them.
The pilot scheme, organised by Keep Scotland Beautiful (KSB), will run for an initial six months over the summer.
There are currently 700 cups in circulation across the 25 businesses.
The Scottish government said its six-year plan for tackling litter and flytipping recognised that it was a blight on our streets, communities and countryside.
Circular Economy minister Lorna Slater believes targeted action, backed by enforcement, will drive behaviour change.
She said: “It is part of a wider package of measures to tackle Scotland’s throwaway culture, including becoming the first nation in the UK to ban some of the most problematic single-use plastics, a commitment to introduce a charge on single-use cups, the introduction of a Deposit Return Scheme, and reform of extended producer responsibility for packaging.”