A Comparative Study on Selecting the General Circulation Model for Pavement Design in China: A Case Study of Beijing

Climate change and extreme weather threaten the global infrastructure. This paper aims to estimate the future temperature rise impact on the asphalt pavement design, especially addressing the performance uncertainty from 32 general circulation models (GCMs) under the SSP2-4.5 and SSP5-8.5 scenarios. We first compare the monthly temperature metrics respectively from historical observations and GCM ensemble simulations in the Beijing area. Five outperforming GCMs are selected respectively for the maximum, minimum, and mean monthly temperature parameters. The 32 GCM ensemble and GCM selection approach contribute a slight difference on the mean level of both the pavement temperature coefficients and lifecycle pavement performance (e.g., fatigue cracking, rutting); however, we observe clear uncertainty reduction for the both perspectives. Comparing to the baseline level (2000–2019), the maximum pavement fatigue life loss of 25% in the 32 GCMs ensemble at the end-century (2080–2099) under SSP5-8.5 can be narrowed to 15% with the selected GCMs. The asphalt layer rutting that may increase to six times the baseline level in the 32 GCMs ensemble can sharply be reduced to three times in selected GCMs case. Therefore, we recommend that the local highway agency should estimate the climate risk uncertainty under a more reliable way, especially with the various engineering adaptation solutions and limiting financial resources in the future.