1. Ph.D. Candidate, Faculty of Engineering, Research Centre for Territory, Transports and Environment, Univ. of Porto, Rua Dr. Roberto Frias, s/n, 4200-465 Porto, Portugal.
2. Assistant Professor, Faculty of Engineering, Research Centre for Territory, Transports and Environment, Univ. of Porto, Rua Dr. Roberto Frias, s/n, 4200-465 Porto, Portugal (corresponding author).
3. Professor, Faculty of Engineering, Research Centre for Territory, Transports and Environment, Univ. of Porto, Rua Dr. Roberto Frias, s/n, 4200-465 Porto, Portugal.