Analysis and Evaluation of Axle Loads on Khartoum-Portsudan Road

Abstract

The deterioration, potholes, ruts, cracks and undulations that are evident on the Sudan roads press the importance of investigating the reasons of these defects and then offering a solution to eliminate them. It is found that axle loading is the main factor affecting road deterioration. Hence, it influences design and maintenance. The overall objective of this project is to evaluate the extent and hence the damaging effect of the level of axle loading on Khartoum – Portsudan Road being the most important case of all roads in Sudan. In addition the research provides a critical review the controlling systems that exist in Sudan highways and their ability to control the load on each axle. Data related to this subject is collected from many sources namely: The previous traffic surveys from National Highway Authority, Statistic Section, Ministry of Finance, Land Transportation Unit, Ministry of Roads and Bridges, The National Chamber for Heavy Trucks, The National Chamber for transport Liquids and Petroleum products, Private Companies such as Al Muntalaq and Ur Transportation Cos. A three days visit to Suakin Weighbridge Station. Chapter one is concerned with Sudan location, topography and climate. It covers also all sections of the project area (Khartoum – Portsudan Road). Transportation modes such as Highway, Railway, pipeline and river modes are discussed. The highway network in Sudan including the existing paved those under construction and those awaiting funds are studied. The identified highway network is about 22,000 km mainly in the South. Chapter two is the theoretical background and literature review which consists of axle load surveying method, traffic counting and axle load studies in African Countries such as Malawi, Ghana, Kenya and Tanzania. Finally the previous axle load studies in Sudan such as highway organization and investment study (HOIS), Axle load control study (ALCS), Pavement Management system (PMS) and Axle load control study for Western Salvation Road. Chapter three is about data collection and analysis. It consists of: Traffic volume for all sections of Khartoum-Portsudan Road, data of overloading from private companies and data from Suakin weighbridge station which was represented by 805 records of vehicles crossing the weighbridge and about 100 records of vehicle that the load on each axle was taken. Chapter four covers axle load analysis and axle load forecasting up to year 2025 applying regression analysis and Gross Domestic Product growth rate. Chapter five includes the findings, conclusions and recommendations. It was found that the average Equivalent Standard Axle (ESA) for Heavy Vehicle is equal to 39, while the average for all vehicles is equal to 14. The ESA for 100 commercial axles is equal to 654. The ESA per ton is equal to 0.52. When comparing the levels of ESA in Sudan with the other industrial countries, it is found that the ESA per 100 commercial axles in Sudan is greater than that in United Kingdom and France by (14) to (7) times respectively. Axle overloading has direct effect on roads age and maintenance. The cumulative equivalent standard axle is expected to increase due to the investment expansion in the country. It is expected to pass the level of 47,000,000 ESA for PortSudan-Khartoum at the end of year 2025 which is classified as very heavy traffic. The National Highway Authority is expected to implement the right polices to control and eliminate the overloading equivalent standard axles.