In this paper, the evolution of the railway traffic during the last century is considered in order
to estimate the remaining service life of a historical bridge. The selected case-study concerns the El Ourit
Bridge designed in 1889 by Gustave Eiffel and located close to the town of Tlemcen, in Algeria. The response
of the bridge to train loads is numerically evaluated using a finite element model of the structure. The
element most affected by stress variations is identified. The fatigue damage in this element is then quantified
by adopting the Palmgren Miner accumulation model. A fully probabilistic approach is adopted by formulating
a limit state function based on this criterion and by assuming that the stress amplitude, the fatigue
strength, and the damage threshold value play the role of random variables. The obtained results are discussed
in order to evaluate the residual service life of the bridge.