Presentation on theme: "THE SIX KEY QUESTIONS Afternoon, Tuesday 16 Nov. Morning, Wednesday 17 Nov."— Presentation transcript:
THE SIX KEY QUESTIONS Afternoon, Tuesday 16 Nov. Morning, Wednesday 17 Nov
Summary of questions 1. Is a road network really the best way to improve access to services? 2. Which network should be chosen? 3. What type of road is most appropriate for the traffic forecasted? 4. How much will it cost? 5. What techniques for construction and maintenance are the most appropriate? 6. What must be done to ensure that knowledge and funds are available?
Is a road really necessary? Roads are part of a transport system (without traffic useless) Invented to allow use of wheeled vehicles Expensive to resist wear from motor vehicles and weather so must provide savings for users Savings must be passed on as lower fares or better service Road improvements require careful planning to make sure that they are used for the benefit of the community
Which roads best meet local needs? Rural roads are part of a hierarchy of networks: below them are tracks and paths, above, secondary and main roads (lots of overlap) Low-volume rural road networks link villages to secondary roads and vehicle transport A coherent core network, consisting of most cost- effective roads, must always be defined The core network must maximise accessibility and be affordable and sustainable Selection can be by economic evaluation but better by basic access or IRAP.
What type of road is most appropriate for the traffic expected? Motor traffic is low (less than 20vpd), but lots of two-wheelers and walkers For sustainablity the level of service should be low (average speed 30-40kph, narrow, bumpy): the good-enough road Forget about national technical standards: not sustainable Spot improvements favoured: concentrate on black spots and drainage Make sure that a solid preventive maintenance system is in place to conserve assets We will look at low-volume road construction in more detail on
What techniques for construction and maintenance are the most appropriate? There are three choices: machine-based; labour- based, or something between the two Use of heavy machinery is not sustainable economically or environmentally for rural roads, but it is institutionally Use of labour-based techniques is more sustainable but not institutionally Use of intermediate techniques recommended Labour-based maintenance almost obligatory We will go into more detail on these issues in the sessions on rural road construction and labour-based works
How much will it cost (1) ? Factors which determine cost Present condition of road Technical standards of upgrade (width, surface, structures, slopes and curves Level of service to be provided (speed, comfort, closures, restrictions) Climate and topography Numbers of heavy vehicles Trade-offs: investment v maintenance Need to minimise environmental footpring (wather management)
How much will it cost (2)? Rural networks are extensive: rapid condition inventories are necessary to find out their present condition, work to be done, and expected cost For main and secondary roads automated recording methods exist (video, gps, roughness indicators) Low volume rural road assessment needs simpler and cheaper methods Visual assessment (drive through) is used with minimal measurement, relying heavily on defined categories This provides the basis for quantifying the work needed to upgrade
Road condition categories Deformation due to material loss Deformation due to material loss Deformation due to subsidence Deformation due to subsidence Extent of rutting Extent of rutting Extent of corrugation Extent of corrugation Severity of potholing Severity of potholing Longitudinal gullies Longitudinal gullies Lateral gullies Lateral gullies Extent of mud formation Extent of mud formation Severity of dust Severity of dust
How much will it cost (3) Visual assessment has provided the basis for quantifying the work needed to upgrade Unit costs can be applied to calculate total lifetime costs for each road section They can be prioritized using cost-effectiveness indices: population/cost, VOC savings/cost Development indices can be assigned, for example to poverty pockets, to prioritise road links in defined areas Finally, coherent networks can be made up of the priority road links A staged construction plan can be defined, respecting investment funds available and local maintenance capacity,
How can we ensure that knowledge and funds are available Management must be decentralised but with higher level support to ensure sustainability Selection of core network requires collaboration between communities and higher levels of government Construction should involve community to train local enterprises, inject wages, instil sense of ownership, and train for maintenance Maintenance should be by local small firms or individuals, managed locally, and quality supervised by an elected user committee All this requires initial and followup training for managers, technicians and local firms: (expensive and risky: sustainability of structures will require continuous higher level support)
How can we ensure that knowledge and funds are available? Contruction funding must come for outside (government and donors): costs far to high for communities or lowest level of government Local contributions to construction symbolic, used sparingly only if shown to be motivational Maintenance costs should be shared with higher levels (matching grants) as roads benefit external interests Financing should be multi-year and aligned to needs Major beneficiairies (traders) should contribute: tolls, trading licences, market tax. If they contribute they should have a say in supervision
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