Passengers travelling in public transportation networks often have to use different lines to cover the trip from their origin to the desired destination. As a consequence, the reliability of connections between vehicles is a key issue for the attractiveness of the intermodal transportation network and it is strongly affected by some unpredicable events like breakdowns or vehicle delays. In such cases, a decision is required to determine if the connected vehicles should wait for the delayed ones or keep their schedule. The Delay Management Problem (DMP) consists in defining the wait/depart policy which minimizes the total delay on the network. In this work, we present two equivalent Mixed Integer Linear Programming models for the DMP with a single intial delay, able to reduce the number of variables with respect to the formulations proposed by literature. The two models are solved by a The research is part of the project "Analysis and Optimization of Intermodal Public Transportati...