**5. Conclusions**

The main goal of this study was to present and discuss a semi-automatic and unbiased procedure to select the most reliable ANN model for a given predictive modeling problem, which can overcome the limitations of conventional approaches. In particular, the focus was on predicting at once volumetric properties and mechanical characteristics of bituminous mixtures prepared using different types of bitumen and aggregate, binder content and maximum nominal grain size, to support the mix design phase, providing numerical estimations of the investigated parameters without any other costly laboratory test. The study results can be summarized as follows:


It is worth recalling that the proposed model is applicable only to the specific types of aggregate, bitumen and mixture structure considered. This study did not account for the influence of different aggregate gradation on the results for a specific bitumen content. An interesting further development would be to investigate such an effect, integrating new input variables related to aggregate gradation or mix proportioning. Alternatively, the modeling variables relating to the mechanical characteristics of the mixture could be replaced by those relating to the road pavement performance, such as fatigue and

permanent deformation resistance. This replacement would represent further progress towards a performance-based mix design.

**Supplementary Materials:** The following are available online at https://www.mdpi.com/article/10 .3390/app112411710/s1, Table S1: Laboratory test results and specimens' characteristics.

**Author Contributions:** Conceptualization, M.M., M.D., E.M., C.M. and N.B.; data curation, M.M., M.D., F.R., E.M., J.V., C.M. and N.B.; formal analysis, M.M., M.D., F.R., E.M., J.V., C.M. and N.B.; investigation, E.M. and N.B.; methodology, M.M., M.D., F.R., E.M., J.V., C.M. and N.B.; software, M.M. and M.D.; supervision, E.M., C.M. and N.B.; validation, M.M., M.D., F.R., E.M., J.V., C.M. and N.B.; visualization, M.M., M.D., F.R., E.M., J.V., C.M. and N.B.; writing—original draft, M.M., M.D., F.R., E.M., J.V., C.M. and N.B.; writing—review and editing, M.M., M.D., F.R., E.M., J.V. and N.B.; resources, E.M. and N.B. All authors have read and agreed to the published version of the manuscript.

**Funding:** This research received no external funding.

**Data Availability Statement:** The data that support the findings of this study are available from the Supplementary Materials.

**Conflicts of Interest:** The authors declare no conflict of interest.
