In contemporary societies, critical infrastructure systems, including road transportation networks, play a key role in ensuring the mobility of people and goods. The recent increase in extreme and unpredictable events, such as those caused by climate change, underlines the need for strategies to strengthen the resilience of transportation road networks against disruption events. This thesis discusses vulnerability analysis of road traffic networks in simulated extreme events (floods), focusing on the use of open data and open-source software tools. The study aims to evaluate the resilience of road networks by proposing two methodologies: GIS-based spatial and topological vulnerability analysis, and vulnerability analysis with mesoscopic simulation of traffic demand to quantify road network traffic performance and functionality.