Managing SADC Roads Agencies in the New Millennium: The Role of Road Asset Management Systems
The management of the Southern African Development Community’s (SADC) road network is a complex task which is often influenced by a variety of factors – technical, financial, social and political – which all enter into the decision making process at various levels of their roads agencies. In such an environment, the determination of optimal strategies requires the use of a rational “systems” approach to road asset management. This paper outlines the road management strategy that is being pursued in a number of countries in the SADC region. It then illustrates how these systems are being used at various levels of application to achieve the desired objectives of the road agency.
Review of sub-Saharan African gravel roads management system: Tanzanian case study
The construction of new networks of gravel roads needed by sub-Sahara Africa will eventually come to completion. Furthermore, many of the gravel roads constructed or rehabilitated between 2005 and 2008 have come to the end of their design lives and during their life cycle, difficulties were experienced in getting required funds for maintenance. What is becoming apparent to the governments and road agencies of sub-Sahara Africa is the urge to conserve, as national asset, the gravel roads network, through the use of operational road management systems. Based on the above mentioned desire, the sub-Saharan African countries, including Tanzania, are exploring ways of strengthening the management of roads transport infrastructure. Towards that end Tanzania have two organisations responsible for managing its road networks, namely Tanzania Road Agency (TANROADS) and Local Government Authority (LGA)’s district engineer’s office. TANROADS is responsible for the management of trunk and regional road networks, while LGAs are responsible for the management of districts road networks. Each of these road agencies uses its own road management system. TANROADS uses Road Maintenance Management Systems (RMMS), and LGA uses District Roads Management Systems (DROMAS). Both these systems have been developed with experts and financial assistance from foreign countries, with involvement of local experts at ministerial or top managerial levels. This paper discusses and points out factors affecting the efficiency and effectiveness of these systems in gravel road management in comparison with those in the developed world. It is expected that ironing out those aspects of management
DEFLECTION ANALYSIS OF FLEXIBLE PAVEMENTS
THREE PARAMETERS ARE USED TO DESCRIBE THE DEFLECTION BASIN CURVE: (1) DYNAFLECT MAXIMUM DEFLECTION, (2) SURFACE CURVATURE INDEX, AND (3) BASE CURVATURE INDEX. MEASUREMENTS PROVIDE A MEANS OF ANALYZING THE BEHAVIOR OF THE PAVEMENT STRUCTURE. THE IBM 360 COMPUTER AND CALCOMP PLOTTER WERE USED IN THE ANALYSIS OF THE DEFLECTION BASIN SHAPE AS WELL AS IN TEMPERATURE AND LAYER EQUIVALENCY STUDIES. THE OBJECTIVE OF THE TEMPERATURE STUDY WAS TO FIND A CORRECTION FACTOR TO USE IN ELIMINATING TEMPERATURE AS A VARIABLE IN DEFLECTION MEASUREMENTS. IT WAS FOUND (1) THAT THE DEFLECTION-TEMPERATURE RELATIONSHIP COULD NOT BE SEPARATED FROM THE MANY OTHER VARIABLES INVOLVED, AND (2) THAT VARIABLES SUCH AS AGE AND SEASONAL VARIATION HAD A LARGE EFFECT ON THE TEMPERATURE-DEFLECTION CURVES. IN THE AREAS OF LAYER EQUIVALENCE, EMBANKMENT HEIGHT, OVERLAY DESIGN AND CONSTRUCTION CONTROL, A GREAT AMOUNT OF USEFUL INFORMATION WAS ACCRUED. AN OVERLAY DESIGN PROCEDURE BASED ON DEFLECTION WAS ESTABLISHED. AREAS OF WEAK EMBANKMENT COULD BE DETECTED PRIOR TO INITIAL SURFACING ALLOWING CORRECTIONS TO BE MADE. ALSO, MINIMUM EMBANKMENT FILL COULD BE DETERMINED WHICH THE DESIGNER COULD USE WITHOUT APPREHENSION. USING THE DYNAFLECT FOR CONSTRUCTION CONTROL INCORPORATED ALL LEVELS OF CONSTRUCTION; HOWEVER, TO BE UTILIZED SATISFACTORILY ON EMBANKMENT MATERIALS, THE EMBANKMENT MUST BE GRADED TO A SMOOTH SURFACE TO ALLOW ACCESS TO THE TEST AREA. RESILIENCE, AGE OF SURFACING, DENSITY, MOISTURE, SOIL SUPPORT, AND VOLUME OF TRAFFIC ARE TREATED BRIEFLY. RESILIENCE WAS FOUND NOT TO EXHIBIT THE STATEWIDE VARIATION THAT HAD BEEN ANTICIPATED. FOR THIS REASON RESILIENCE WAS ELIMINATED AS A SIGNIFICANT FACTOR. AGE OF SURFACE, SOIL SUPPORT, AND VOLUME OF TRAFFIC ARE INCLUDED. /FHWA/