Assessing the effectiveness of signs to change littering behavior in a Norwegian national park

Littering in natural areas disrupts ecosystems and diminishes visitor experiences, posing a persistent challenge. This study explored how communication through signage could effectively reduce littering behavior. We tested two signage interventions at six campsites near Røvoltjønnan Lake in Femundsmarka National Park, Norway, using insights from visitor interviews and observations structured by the COM-B and the elaboration-likelihood models. Field experiments conducted in summer 2023 measured effectiveness through waste mapping, visitor surveys, and trail counters. Daily litter at the campsites ranged from 0 to 16 pieces, with an average of 13 pieces during the control period. Treatment period 1 (Sign 1), reduced this to 7 pieces, and treatment period 2 (Sign 2) to 4 pieces. Overall, there was a 59 % reduction in litter at campsites when the signs were implemented compared to the control period. While Sign 2, with larger font size and image, appeared more effective in reducing littering, the difference between the signs was not statistically significant, likely due to limited sample size. Most visitors already exhibited responsible behavior by taking their waste home and expressing a strong belief in the importance of not littering, suggesting that explanations and justifications included in Sign 1 were unnecessary. The signs likely served as reminders, increasing attentiveness and encouraging visitors to take all their waste with them, with some picking up litter left by others. These findings highlight the importance of targeted communication in fostering stewardship and providing actionable insights for park managers to reduce environmental impacts and promote sustainable visitor behavior. Management implications: • Information signs can effectively reduce littering in outdoor recreation and nature-based tourism • Signs related to proper waste disposal may function as reminders of already established social norms and attitudes • Signs can be successful when reinforcing easy behaviors that do not require complex messaging or mental processing • Larger fonts, images, and minimal text on signs can encourage more people to read the message