A large number of Australian rail bridges were constructed over 80 years ago and the rail industry is suffering from their ever increasing maintenance costs and continued budget constraints. Making informed decisions for condition assessment, cost effective inspection, maintenance including repairs, upgrades and replacements with inadequate and sometimes inaccurate data and limited resource is a major challenge. Moreover, this limited access to actual data causes a great level of uncertainty in the management of railway bridges. In addition, bridge managers are expected to maintain these assets at specified performance levels with ongoing budget cuts and resource constraints. On the other hand, there is an increasing demand for bulk material transport leading to increasing axle loads to cope up with capacity constraints. Because of these reasons it is currently taking staff a longer time to plan and prepare maintenance budgets, analyse, interpret and take decisions for bridge life management. Most of the available bridge management systems are generic and analyse faults at the system level. In many cases, a detailed analysis at the level of individual components is needed to have a better understanding of potential root causes and focussed decision on bridge life extension. Consequently, a research project is being conducted on this issue and this paper proposes a practical bridge life management decision model using degradations, defect initiation and growth, maintenance options and relevant costs. The objective is to provide a practical, cost effective and user-friendly way to make maintenance decisions. The outcome of this research is a faster, more accurate system for informed decision making capability for cost effective life cycle management of railway bridges.