The suitable functioning of traortation facilities is based on having good infrastructure, trusted fleet and regulations. In many countries, due to lack of research and also resource limitations, intensive field work has not been performed and from the beginning, edition of pavement design codes carried out with the help of codes prepared in developed countries. It seems it is in such a condition that proper coordination among fleet, pavement condition and weight rules does not exist. This results in economic loss, decreased safety and traffic chaos. We should consider that generally all the society could sense the benefits of freight shipping, but governments are usually paying to provide and upkeep the infrastructure. It seems pavement damages constitute a major contribution in traortation cost, therefore damage Assessment does help to find the effective strategies to reduce related costs. The scope of this research is to evaluate damages on pavements, defining “truck factor per ton” for different inter-ideograph; TEXT-ALIGN: justify; LINE-HEIGHT: normal; MARGIN: 0in 0.2pt 0pt 0in; unicode-bidi: embed; DIRECTION: ltr" Two approaches are considered here to evaluate load-related damages on pavements. First, using permitted axle weights and second, assessing related damages based on load spectra. Also, a comparison in damages resulting from enforcing past and new regulations has been done. The results indicate that there would be an optimum proportion of heavy vehicles in traffic stream that minimize the load-related pavement damages. Also in shipping a constant tonnage of goods, smaller numbers of fleet would be sufficient. In addition, designing pavements based on permitted axle weights are safe and conservative. Keywords : load spectra, permitted truck weight, weight in motion, optimum truck fleet
