Adjustment to traffic load data for highway bridge

Presently applied traffic load data for highway bridges is flawed in terms of statistical method, considerably jeopardizing the accuracy of the results of related studies. In order to have it rectified, Gumbel distribution is adopted in this study, and based on the data for daily maximum distribution collected by previous research, revised data for a range of periods of 30 days, 1 year, 10 years and 100 years is computed. The error induced from the roughly approximated time-interval for annual distribution is significantly refined and the change of data with different considered periods is clearly presented. Result of the paper goes better with the practical situation, diminishes possible mistakes that might be derived from the use of traffic load data and provides important reference for data collection work in the future.