Effects of Non-Implementation of Axel Load Regime on Karachi – Hyderabad Motorway (M-9)

Abstract

Pakistan is facing a serious challenge of overloaded vehicles all over the country. Road infrastructure is subjected to much higher axle loadsas compared to its design capacity/ strength. Heavy axle loading coupled with materials inadequacies, construction practices andclimateis causing rapid road deterioration in Pakistan. Truck drivers and owners consider overloading as a profitable practice unaware of the adverse effects on the pavement resulting in serviceability losses. Data from forensic investigations conducted earlier to identify causes of pavement failure within six months at some stretches of slow lane of Karachi Hyderabad Motorway M-9have been utilized/ referred in this study.The main factor of slow moving uncontrolled loaded trucks on slow lane resulted indistresses/ rutting/densification of pavement layers. In order to evaluatetraffic overloading effects on M-9 motorway, field traffic dataon Karachi-Kathore and Hyderabad-Bolari Sections have been analyzed. Comparative analysis has been carried out on traffic data between year 2015 and 2019/2020. Based on traffic growth observed,level of service (LOS)analysishas also been included in this study.We have based ourstudy on the damage caused by heavy overloaded vehicles, in this regard an axle load violation in excessof 2,4,6,8 and 10 tonnefrom the standard axle load limits of Pakistan were considered. Moreover, penalty in the toll rates for overloaded vehicleshave been proposed based on the overloading magnitudeandrigid pavement in the outer/ slow lane have alsobeen suggested.