What is Systematic Pavement Design?

Pavement design is about choosing the most cost-effective option of pavement thickness and composition to provide a sufficient level of service for the anticipated traffic.

To achieve this goal, the designer must have sufficient knowledge of the materials, the traffic, the local environment – and their interactions – to be able to predict the performance of any pavement composition. In addition, the designer must have knowledge of what level of performance, and what pavement condition, will be considered satisfactory in the circumstances for which the pavement structure is being designed.

Because of the many variables and interactions which influence the result, it is appropriate to adopt a systematic approach to pavement design. Depending on the amount of data which has to be provided or, conversely, on the number of assumptions which have to be made, a pavement design procedure may be very complex at one extreme or very simple at the other.

Sound pavement performance depends on a number of factors and relies on a ‘cradle to grave’ approach, managed by experienced professional staff. The primary factors are:

• design – including materials assessment and pavement composition

• construction – to meet design requirements, including quality, tolerances and drainage

• maintenance – to maintain pavement integrity

Figure 1 - Demonstrating the relationships between input variables, analytical methods and the decision processes which comprise pavement design.

Therefore, because of the many variables and interactions which influence the result, it is very much appropriate to adopt a systematic approach to pavement design. Depending on the amount of data which has to be provided or, conversely, on the number of assumptions which have to be made, a pavement design procedure may be very complex at one extreme or very simple at the other.