D4: Life cycle costs for structures, particularly bridges

1 Bridges in Great Britain nowadays are designed to last for 120 years although this figure apparently has never been Justified by anything lore than the intuition of the committee that chose it.

2 In fact durability is the product of many highly variable factors which are of fundamental importance in considering actual life cycle costs.

3 History indicates that for many bridges the specified life cycle may be optimistic and arguably may even be too long considering the fast changing needs and aspirations of society.

4 Although a few older structures still exist, sost engineering structures have been built in little more than 200 years since Watt's steam engine heralded the industrial revolution.