Longevity Facts
In the UK, modern asphalt roads are designed to last at least 40 years before they require major construction work. However, in practice they last much longer. The Annual Local Authority Road Maintenance (ALARM) Survey for 2000 found that half of Britain's roads have had no, or only minor repairs in the last 40 years and four per cent have been unrepaired for 100 years.
A number of criteria is taken into account when deciding the design life of a road for example, initial capital costs, on-going maintenance costs, and congestion costs caused by re-construction or repair.
Road design software enhances the longevity of asphalt roads by using mathematical models to predict performance on the basis of the road as a multi-layered structure. Computer programs allow design engineers to calculate the stresses and strains, in the model road, generated under varying conditions.