Dartmoor National Park Authority plans to scrap parking honesty boxes in favour of ticket machines in a bid to get drivers to pay up.
Visitors to Dartmoor have been asked to make the £1 voluntary contribution for the past six years with the money going towards the upkeep of the countryside.
But the average donation per vehicle has been just 15p - creating a huge shortfall in funds. In a bid to combat motorists who avoid paying, the Authority introduced a trial pay and display scheme in Princetown in the heart of Dartmoor - and seen revenue soar four-fold.
Some people think, 'If I don't have to pay, I won't bother' - it's just human nature
Andrew Watson, head of recreation, access and estates at Dartmoor National Park
Under the previous scheme and annual income in the village for parking was just £6,000 but it has now increased to £24,000.
The park authority now wants to bring in parking meters at car parks in Meldon, Newbridge, Postbridge and popular tourist spot Haytor.
They would charge visitors an hourly rate instead of the optional one-off donation and say money raised would go towards maintaining the car parks.
Head ranger and emergency officer Robert Steemson said: "An honesty box is an honesty box - people can choose to put money in if they want. But with compulsory machines, people will turn up and pay or move somewhere else."
Andrew Watson, head of recreation, access and estates at Dartmoor National Park, added: "Some people think, 'If I don't have to pay, I won't bother' - it's just human nature.
"We thought the new pay and display might deter people at Princetown but that has not been happening. Most people expect to pay and we will charge £2 for a full day's parking."
But despite that some locals are furious at the plan - and say a lot of the money will go back to the machine operators and not into the local area.
Jan Jackson, 57, said: "At least with an honesty box all monies go to the people who put them there. I daresay that these machines will be leased from operators, and only a cut will go back to the organisation.
"The potential income to Dartmoor from these machines might well go down, especially if people don't want to pay.
"They will just look for a handy roadside pull in, instead - which will then impact other vehicles using the roads."
Joy Easterbrook, 55, added: "It might put people off stopping to see Dartmoor."