Rational Procedure for Determination of Rut Depth Intervention Level in Network-Level Pavement Management

Rutting is a common distress form found in asphalt pavements and is known to be a potential road safety hazard that can lead to skidding or hydroplaning accidents in wet weather. Ruts are formed along pavement wheelpaths under repeated traffic loading. They present a safety risk to vehicles because they collect water during wet weather, which can lead to reduced skid resistance along the rutted wheelpaths because of the presence of water. It is necessary to repair medium or severe pavement ruts to ensure wet-weather driving safety. However, there is not a commonly accepted quantitative basis for determining the maintenance threshold for repairing pavement ruts. Most highway agencies today rely on experience and engineering judgment in setting the rut depth threshold for activating rut repair. This paper presents a study to develop a rational analytical procedure for a quantitative determination of rut depth intervention level based on the concept of skid resistance intervention level. The procedure makes use of a finite element simulation model to compute skid resistance. For easy practical application, either a database or neural network model can be adopted to expedite the analysis. The proposed procedure offers a method of determining rut depth intervention level on a basis consistent with the concept of skid resistance intervention level for pavement friction management. Numerical examples are presented to illustrate the application of the proposed procedure and highlight its potential for implementation in a network-level pavement management system.