Residents complain that the visitors drive dangerously, block roads, pull over on the main carriageway to take pictures of Highland cows, and block traffic with slow convoys of dozens of motor homes.
One woman taking her husband from Sutherland to Raigmore Hospital in Inverness said an hour-and-a-half had been added to her driving time each way.
Highland councillor Kirsteen Currie said: “No one wants to talk about the problems associated with the North Coast 500. It is like we have set up a Disneyland where people can come and look at us in our nice wee rural lives, as they whizz by in their camper van or sports car.
“But this is real life and it can be very frustrating. It is not sustainable.
“I often hear stories of health visitors and other staff in the NHS who are trying to get out to do home visits, and journeys that would be 20 minutes in the winter take more than an hour when the NC500 is in full swing.
“Or there’s police officers who have to give up other work to come and help a motor home reverse.
“People used to come and stay for three or four nights. People now come for one night as they try to race around the area, the size of a small European country, in two days.
“It is not sustainable, and we need to talk about it seriously.”
Frustrated driver Lilly Mather, from Tongue, said she had an extra 90 minutes added to her journey to and from her local hospital.
Mrs Mather said: “I have been taking my husband for chemotherapy in Raigmore. I went down in the last week in March and it took me just over two hours.”
Singer Karen Lupton-Garcia said she was shocked when a tourist stopped right in front of her between Mid Clyth and Occumster on the A99 to take a picture of Highland cows in a field.
She said: “They almost caused a serious accident. They were completely oblivious.”
However, Councillor Raymond Bremner, who lives on the east coast at Thrumster, Wick, said: “It’s been a welcome boost and one that I can see will continue to appeal to greater numbers of visitors nationally and internationally as visitors tell others about their experience.”