Temperature field characteristics of asphalt pavement in typical sections along the Qinghai-Tibet highway

To address low sensor survival rates and external errors in monitoring the Qinghai-Tibet Highway, this study proposes an inverse method to derive pavement temperatures from stable subsurface thermal data within the roadbed. Validated at a test site, the method showed excellent agreement. It was applied to six representative sections to analyse spatio-temporal characteristics. Results revealed significant regional variations: maximum pavement temperatures followed a ‘high-low-high-medium-high’ pattern from north to south, ranging from 13.52°C to 21.79°C, while minimums ranged from −12.31°C to −7.70°C. High temperatures peaked in June–July, and lows in January. The study emphasizes that regional pavement temperature variations must be considered in permafrost highway thermal stability assessments. This method provides a reliable alternative for data acquisition in harsh environments.