Transport has a critical role in economic development; an efficient transport system can enable economic growth and enhance social well-being. Road networks, as a part of a transport system, are among the most important lifeline systems. Urban road networks experience serious congestion because of infrequent major disruptions. Due to these disruptions the traffic system performance is reduced and the travel time and emissions in a road network are increased. This thesis describes a method for optimising traffic signal settings (i.e. green times and offsets) to assist drivers to avoid partial or complete blockages, to minimise the travel time or carbon dioxide emissions in the case of disruptions in road networks. This involves different capacity degradations (i.e. 25%, 50%, 75%, and 100%) with various durations (4 minutes, 20 minutes, 36 minutes, and 60 minutes). The Cross-Entropy optimisation method is applied, along with a static then a semi-dynamic approach, to optimise traffic signal control in disrupted road networks. This includes investigating two objective functions: minimising the travel time or minimising carbon dioxide emissions. The results for minimising the travel time, on the Cambridge (UK) network, show that applying the proposed method reduces the travel time by almost 6% in the case of a complete capacity reduction at the most congested node in that network, compared to not applying this approach. In terms of minimising carbon dioxide emissions, applying the proposed approach can result in almost an 8% reduction in the carbon dioxide emissions, in the case of a complete capacity reduction compared to not applying the proposed approach. An implication of these findings is that signal optimisation could be used as a means of reducing the travel time and CO2 emissions in disrupted networks. This thesis comprises two main parts divided into seven chapters. Part one provides an introduction chapter and literature review of the resilience of urban road networks, modelling disrupted road networks, traffic signals optimisation, and emissions modelling. Part two presents the formulation of the problem and solution methods, to optimise traffic signal control in disrupted road network.