ABSTRACT
Traffic load is one of the most critical factors that influence a bridge design, analysis and maintenance. Important traffic load information includes the most possible maximum gross vehicle weight during the design return period. The extrapolation and statistical analysis are frequently employed to obtain the most possible maximum gross vehicle weight within the design return period. The extrapolation approach was proposed by Nowak (1994). This approach provides an easy and effective way to obtain the maximum value of related parameters. It can avoid complicated simulation. Nowak (1994) used this approach to obtain the traffic load model of the Ontario Highway Bridge Design Code. However, the approach is subjective and the accuracy depends on the experience of the researchers. The statistical analysis approach is an effective method to obtain the cumulative distribution function (CDF) of gross vehicle weight and axle weight. Miao and Chan (2002) used this approach to obtain the traffic load model for Hong Kong. The disadvantage of the statistical analysis approach is its complexity.
