Reliability analysis of infrastructure assesses the probability of structural failure by determining if safety limits are exceeded. It evaluates both the probability of failure and statistical properties like probability distributions and confidence intervals of structural responses. Structural reliability is assessed by comparing the probability of exceeding boundary states, such as ultimate limits related to collapse, or serviceability limits related to normal usage disruptions, to required values. Reliability is differentiated according to consequence classes, with recommended minimum reliability indices provided to achieve appropriate levels of safety for structures with high, medium, or low consequences of failure.