**5. Conclusions**

The managemen<sup>t</sup> of road transport risk involving hazardous substances is a challenging exercise because the factors influencing this variable depend on the vulnerability of the medium as well as on a myriad of road accident causes and circumstances. The challenge also results from the fact that, to be effective, a risk managemen<sup>t</sup> tool needs to release the relevant information on local vulnerability immediately after the occurrence of an accident that spilled a dangerous product over the road. In this study, a combination of vulnerability and hazard assessments proved efficient to readily identify risky sections in a segmen<sup>t</sup> of highway BR 050 located in Brazil, which correspond to areas with a larger incidence of accidents located on strongly vulnerable areas. In these areas, the risk is mostly determined by ground slope and drainage density. The study could also depict accident sites and associated influence buffers as colored circles to readily represent vulnerability at site scale. It became evident at first sight that the southern sector of the highway BR 050 segmen<sup>t</sup> requires closer attention as regards environmental risk. In case of accident, soil and water contamination is highly probable because soils and geological formations are barely capable to sustain the propagation of contaminants in that sector. Overall, the study proved efficient in providing a comprehensive diagnosis on contamination risk along the studied road, as well as in providing clues about sectors of the highway requiring particular attention from risk managers.

**Author Contributions:** E.R.M. contributed to resources, data curation, investigation, conceptualization, methodology, and writing original draft. R.F.d.V.J. and T.C.T.P. contributed to formal analysis, supervision, project administration and funding acquisition. H.E.S. contributed to software and visualization. L.F.S.F. contributed to formal analysis, validation, writing-review, editing, and funding acquisition, F.A.L.P. contributed to funding acquisition, methodology, supervision, and writing-review editing.

**Funding:** As regards the Portuguese authors, the research was funded by national funds (FCT-Portuguese Foundation for Science and Technology) under the strategic project of the Vila Real Chemistry Research Center (PEst-OE/QUI/UI0616) and the CITAB (Centre for the Research and Technology of Agro-Environmental and Biological Sciences) project UID/AGR/04033.

**Acknowledgments:** The authors would like to thank the Federal Institute of the Triângulo Mineiro (IFTM) for their support with infrastructure and software for the development of the research, and the road company MGO Rodovias for the availability of data. The authors also wish to thank the University of Trás-Montes and Alto Douro (UTAD), the Chemistry Research Center and the Center for the Research and Technology of Agro-Enviromental and Biological Sciences (CITAB), for technical support.

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