Distribution Function Similarity of Overloaded Commercial Trucks Detection (Case Study: Iran)

Monitoring overloaded vehicles is an operational aspect of ensuring the safe operation of vehicles and mitigating damages to road pavement. Since, the concentration on overloading is claimed to differ for the type of trucks, where trailers are more allegedly engaged under enforcement, this research aims to explore the differences in overload monitoring among various kinds of vehicles, including trailers, heavy trucks, and light trucks in intercity transportation. To this purpose, at the first stage, the effect of the number of weighing stations and cargo trips on overloading detection has been investigated through analysis of variance. It is followed by considering the number of registered trucks as an exposure factor to standardize the enforcement rate in the second stage. An adapted version of the statistical method of Kolmogorov-Smirnov, known as three samples, is finally utilized to investigate the similarity of distribution functions of overloading detection for three types of trucks including trailers, heavy trucks, and light trucks. Data, for registered trucks as well as detected trucks as overloading across the road network in the West-Asian country of Iran, has been collected for a year followed by categorizing into thirty-one provinces. The results revealed that whereas the number of weighing stations and cargo trips do not have significant effects on overloading detection, the similarity of distribution functions for overloading detection is different for three types of trucks over the provinces. Therefore, all types of trucks are not equally under overloading control and transport authorities should redesign overloading detection approaches throughout the enforcement instruction applied in intercity transportation.