Load Damaging Effects of Overloaded Trucks on Federal Highway Pavement Structures in Nigeria

The goal of the study is to determine the current serviceability rating of Nigerian roadways as well as the effects of overloaded trucks on load damage. The American Association of State Highway and Transportation Officials (AASHTO) techniques were used by the researchers. In this study, the highway section of Lokoja-Abuja, Ilorin-Jebba and Abakiliki-Ogoja via Mbok roads were selected, and data were collected through an axle-load survey, automatic traffic count and from secondary sources. Traffic data was collected within four months beginning from January 2019 using weigh-in-motion facilities operated by Exosphere Nig. Ltd. The gross vehicle weight (G.V.W.) of all vehicle categories, was obtained from a weigh-in-motion system installed on survey points. A thorough analysis of the vehicle data was obtained to determine the vehicle overloading characteristics at the study location. The percentage of gross vehicle weight violation was discovered to be anywhere between 20% and 94 percent of the axle load distribution over the network tested. When the overloaded vehicle damage factor (V.D.F.) was compared to the standard V.D.F., the difference was between 1.2 and 41.34 times across the road networks investigated, explaining why the pavement constructions of Nigerian roads deteriorate so quickly over their service life. The current serviceability ratings on the Lokoja-Abuja, Ilorin-Jebba, and Abakiliki-Ogoja roads were evaluated to be 3.45, 4.41, and 3.35, respectively, indicating depletion from their baseline conditions. The damage index g defined the fractional change of serviceability index are 0.30, 0.35 and 0.43 for Lokoja-Abuja Road, Ilorin-Jebba Road and Abakili- ki-Ogoja Road respectively. This ratio explains the loss in serviceability at time t to the potential loss taken at a point where P.T. = 3.0. We propose a more systematic pavement damage estimating process that combines various existing methodology, such as the Highway Economic Requirements System (HERS) and AASHTO methods. The strategy will offer a practical method for estimating the expenses of pavement damage caused by truck traffic on specified pavement segments.