The lockdown and social distancing policies to reduce COVID-19 spread and perceived safety threats of COVID-19 significantly affected people’s travel behavior. Greece has been suffering from the COVID-19 pandemic, and people’s mobility behavior has been greatly affected. This study aims at: (1) exploring the variations in individuals’ trip frequencies by mode and purpose before and after the COVID-19 outbreak; (2) understanding the effects of individual differences (i.e., sociodemographic details) and perceptions towards COVID-19 (i.e., the perceived threats of COVID-19) on people’s mobility behavior changes after the outbreak; (3) underlining the individuals’ perceptions of the COVID-19 threat on the willingness of public transportation usage. Overall, 403 responses were collected in late 2020. A series of random parameter Probit modeling results reveal multiple individual and perception factors affecting the changes in mobility behavior in Greece. The results from structural equation modeling indicate that perceived COVID-19 threats affect the attitudes and subjective norms towards people’s intentions to use public transportation. The results from this study provide valuable insights for transportation authorities to develop effective strategies to manage traffic during the spread of disease for a possible future epidemic.

With a view to enhance road network’s safety, it is crucial to focus primarily on its critical infrastructures, one part of which is tunnels. Fire safety of tunnels concerned intensely the public opinion after the disastrous trans-Alpine accidents in Europe in the late 1990s. Therefore, risk assessment was officially introduced for ensuring the tunnels’ level of safety. Bearing in mind that trapped-users’ performance can strongly determine a tunnel’s level of safety, this paper proposes an evacuation simulation model for increasing the efficiency of quantitative risk assessment. The model aims at acting as an add-in to the traditional computational fluid dynamics models by linking their results with trapped-users’ evacuation. The model structure is twofold. Initially, through estimating potential losses among trapped-users, the effectiveness of important parameters for the safety of the tunnel system is measured. Subsequently, if needed, the performance of additional to standard safety measures is examined. The model aids safety analysts in making better-informed decisions regarding a tunnel’s level of safety. An application example is presented to illustrate the utilization of the model.

Although tunnels provide roads with numerous advantages, they also include significant risks. Especially, fire accidents are the biggest threats. Nowadays, risk assessment has the predominant role for managing tunnel fire safety and users are in the centre of attention. However, existing methods exhibit lack in treating uncertainty stemming from users. This paper aims to discuss current ways of representing tunnel users’ uncertainty as well as to introduce the importance of distinguishing these representations in the wider context of risk assessment.