## 6 Conclusions  
In this study, the tensile properties and viscosity characteristics of ESA binders with different EP contents were first analyzed by laboratory tests. Then, the pavement performance of ESAC and HSAC with different material compositions was investigated, and suitable asphalt mixtures were preferably selected for the trial road construction. Finally, the ERS system and SMAC + EAC structure were evaluated by combining the results of performance tests on the trial road in service for one year. The main conclusions can be summarized as follows:  
1. Using SBS-modified asphalt binder as the asphalt matrix helped to improve the strength and toughness of the ESA binder simultaneously. The increase in EP content enhanced the mechanical strength of the ESA binder but tended to affect the toughness negatively. Additionally, the construction allowable time for the ESA binder was sufficient and exceeded 150 min.
2. ESAC and HSAC had good pavement performance; only the high-temperature performance of HSAC7 and the low-temperature performance of ESAC50 failed to meet the specification requirements. The optimal content of TPS in HAS binder and EP in the ESA binder were finally determined to be 11 wt% and 45 wt%, respectively.
3. The \(\varepsilon_{\text{B}}\) and \(BPN\) of HSAC11 reached 4198 \(\upmu\)c and 94, and the outstanding low-temperature toughness and skid resistance contributed to the reduction of cracking disease in the top layer whilst improving the comfort and safety of driving. The DS of ESAC45 was 22,360 times/mm, and the excellent high-temperature stability and moisture damage resistance provided a stable pavement base for the top layer. Meanwhile, its satisfactory toughness synergized favorably with the steel plate, which limited the generation of cracks as well as reflective cracks in the bottom layer.
4. The service condition of the trial road paved with the ERS system was inferior to that of the SMAC + EAC structure. The trial road paved with the ERS system only had one lane with an SDPQI above 90. In contrast, under the higher traffic volume, the SDPQI of all lanes of the trial road using the SMAC + EAC structure reached above 90. The excellent service performance of this novel steel deck pavement structure validated that its application is feasible and has the potential to be replicated.
5. The service performance of the trial road will continue to be measured in the future to provide further data comparisons and analyses as a basis for promoting the SMAC + EAC structure.  
Conceptualization, [PERSON] and H.G.; methodology, [PERSON]; software, [PERSON]; validation, [PERSON], [PERSON] and J.S.; formal analysis, [PERSON]; investigation, [PERSON]; resources, [PERSON] and J.S.; data curation, [PERSON]; writing--original draft preparation, [PERSON] and J.S.; writing--review and editing, [PERSON] and [PERSON]; visualization, [PERSON]; supervision, [PERSON] and [PERSON]; project administration, [PERSON]; funding acquisition, [PERSON] All authors have read and agreed to the published version of the manuscript.  
This research received no funding.  
Not applicable.  
All data, models, and code generated or used during the study appear in the submitted article.  
No conflict of interest exists in the submission of this manuscript, and the manuscript is approved by all authors for publication. We would like to declare that the work described was original research that has not been published previously and was not under consideration for publication elsewhere, in whole or in part. All the authors listed have approved the manuscript that is enclosed.