Characteristic of a critical network ARC in a service system

Vulnerability of a transportation network influences, importantly, the function of public service systems constituted on the network. To be able to study the importance of an individual network arc for proper functionality of the system, we suggested a characteristic function of the arc transit time elongation together with its upper and lower estimations. We also suggested and verified an algorithm that enables the determination of parameters of the characteristic estimation, and we provide a reader with a computational study performed with real road networks.