Transport infrastructure - roads, railway tracks and stations, ports and airports, and even the most basic rural facilities - all require maintenance, sometimes known as 'conservation'. Maintenance ensures that the asset continues to function as designed or intended, and meet the required quality standards throughout its anticipated lifetime. It can also extend the life of the asset beyond the original 'design life'.
This section focuses in particular on road maintenance or conservation under the following headings:
Types of road maintenance
There are three main types of rural road maintenance: routine, periodic and emergency.
Routine maintenance comprises a range of small scale and simple activities - usually carried out at least once a year - but usually widely dispersed. Typical activities include roadside verge clearing and cutting back encroaching vegetation, cleaning of silted ditches and culverts, patching and pothole repair, and light grading/reshaping of unsealed surfaces. This maintenance may be able to use unskilled/skilled labour, or labour based methods supported by light equipment. Conventional or community contracting may be appropriate. These regular operations are a good opportunity to identify periodic maintenance needs.
Periodic maintenance occurs less frequently - usually after a number of years. Works can include regravelling, resurfacing, resealing and repairs to structures. It is normally large scale and usually requires standard or specialist equipment and skilled resources. Pavement strengthening overlays or pavement reconstruction are normally not considered to be 'maintenance' and are often funded separately under 'development' or 'capital' budgets.
Occasionally urgent, unplanned, maintenance works may also be required - sometimes known as Emergency Maintenance - for example because of particularly severe weather conditions, floods, unexpected deterioration, or damage caused by vehicles.
Why maintenance is important
Timely road maintenance is important because it sustains the quality and safety of the road in a condition close to the original design, and minimises the road user costs. It is also cheaper to regularly maintain a road in whole life cost terms, than to endure an ongoing cycle of un-managed deterioration and reconstruction. The impacts of inadequate maintenance can be felt immediately on the safety of the road and on vehicle performance. The World Bank's note on "Why road maintenance is important and how to get it done" gives a helpful overview of the arguments for timely road maintenance and advice on good practice.
If left unchecked, minor maintenance problems tend to become more serious and more expensive to repair. The South African National Road Agency Ltd. (SANRAL) estimates that repair costs can rise to six times maintenance costs after three years of neglect and to 18 times after five years of neglect. However, finding the necessary funding for maintenance can be difficult.
Planning and funding road maintenance
Road maintenance costs can vary significantly depending particularly on:
It is therefore important to consider the cost of maintenance when planning a route or investment in part of that route, setting appropriate standards and specifications for the road and the approach to contracting and procurement. On lower category roads the involvement of the local community or stakeholders can substantially reduce the operational and overhead costs. At the initial planning stages the 'whole life costs' of the road should be considered as an integral part of the design process - not just the short-run capital costs of the initial construction, but also the long term costs of its maintenance. A realistic assessment of the capability and likelihood of timely road maintenance will be a major influence on the effectiveness of the construction investment. The document Priorities in Improving Road Maintenance Overseas: a check-list for project assessment is a useful guideline to support assessment of maintenance capability.
Frequently problems arise because these road maintenance costs have either been underestimated, or insufficient financial provision has been made for them. The World Bank's Road Costs Knowledge System (ROCKS) provides a source of knowledge on the cost of road maintenance and rehabilitation for different types of road, drawn from different regions. Maintenance can be achieved at lower costs using innovative local-resource-based approaches as discussed hereafter.
It can also be difficult to argue the case for maintenance funding against other priorities. The Norwegian Public Roads Administration has published a useful note on "How to sell the message "Road maintenance is necessary" to decision makers."
The PIARC publication Save Your Country's Roads is a short briefing for decision makers to mobilise support for maintenance initiatives and funding. It is available in a number of languages. Some of the financing reforms discussed in the funding section attempt to address the problems of insufficient or cyclical funding through, for example, the establishment of dedicated road funds.
The cost of maintenance can also often be reduced by better evaluation of condition, prioritisation of works, improved contracting or by the use of more innovative approaches such as labour-based or community contracting in remote or rural areas, or by the use of performance based contracts.
Force account or direct labour approaches were often used by road authorities, particularly for routine maintenance. These approaches have been actively discouraged in recent years due to observed under-performance. However, both force account and private sector approaches have their advantages and disadvantages. Careful assessment of both of these approaches should be in the local environment. A key requirement for either method is to be able to fully cost (especially finance, overheads and equipment replacement costs on a sustainable basis) and monitor performance and take action to remedy any shortcomings.
Up to date network asset (inventory) and needs assessment (from condition surveys) can help to identify and quantify maintenance requirements, estimate works costs and together with realistic performance assessment can help to make bidding and negotiating for funding with stakeholders more successful.
The Asian Development Bank's Road Funds and Road Maintenance is also a useful reference document. The World Bank's Technical Paper No 409; Commercial Management and Financing of Roads provides guidance on the improved conservation of main road networks.
Guidelines for road maintenance
In addition to the guide on "Why road maintenance is important and how to get it done" the World Bank produces a number of guidelines or tools for road maintenance. The Highway Design and Maintenance Standards Model (overview) (presentation) incorporates the research of road deterioration in a number of regions and can be used by planners and management organisations to estimate the total transport costs of alternative road improvement and maintenance strategies through life-cycle economic evaluation. Effort and care must be taken to calibrate and adapt the model for local conditions. The Bank has also provided a number of guidelines to different approaches to contracting, particularly performance-based contracting for road maintenance.
PIARC (World Road Association) has also produced the International Road Maintenance Handbook in 4 volumes which has been translated into a number of languages including French, Portuguese, Spanish, Khmer, Lao, Sinhala and Tamil.
The Transport Research Laboratory has produced a number of key documents including Overseas Road Note 1 'Maintenance Management for District Engineers'; the publication complementary to the Overseas Road Note 2 'Maintenance Techniques for District Engineers'. Overseas Road Note 3, A Guide to Surface Dressing in Tropical and Sub-Tropical Counties, provides guidance on this popular low cost, paved road, maintenance treatment.
More recently TRL produced Overseas Road Note 18: A Guide to the Pavement Evaluation and Maintenance of bitumen-surfaced roads in tropical and sub-tropical countries. Overseas Road Note 20, Management of Rural Road Networks, provides further guidance.
For Routine Maintenance, useful documents include the Headmans Handbook a pocket sized booklet in English and Kiswahili produced for labour based maintenance of earth and gravel roads in Kenya. The Ministry of Transport Vietnam produced the Commune Maintenance Handbook which provides guidance on rural road maintenance from a community perspective.
Bridge maintenance guidelines are provided by TRL's Overseas Road Note 7 (Volume 1), A Guide to Bridge Inspection and Data Systems for District Engineers, and the complementary publication; Overseas Road Note 7(Volume 2), Bridge Inspector's Handbook.
Innovative approaches to road maintenance
Options for maintenance can vary widely according to the type of road and by the type of contracting and procurement systems chosen. There has, for example, been some excellent work carried out to develop labour-based, local and community contracting but the experience has shown that this approach, whilst cost-effective, needs careful planning and usually the oversight and support from road management organisations if it is to be sustained in the long-term.
The labour based 'lengthman' system has been used in various forms in many countries. However the system is dependent on a consistent provision of funds and supervisory support. If this is withdrawn for a period of time, the consequential backlog of work can overwhelm the system and necessitate expensive, large scale rehabilitation.
In rural areas with agricultural activities it is possible to utilise agricultural equipment such as simple wheeled tractors in the rural road maintenance system, with the potential to bring benefits to both sectors if carefully planned. MART Working Paper No 7 and LCS Working Paper No 5 provide knowledge on these approaches.
DfID sponsored the development of "Community participation in road maintenance: Guidelines for Planners and Engineers" by IT Transport Limited and ILO's Employment Intensive Investment Programme (EIIP) and ILO-Asist have extensive guidance on innovative approaches to contracting.
Adequate monitoring of the road network is also necessary to ensure that it performs as anticipated and that maintenance is adequate - particularly where performance-based contracts have been used.
Developments are continually being made to the available technology, materials and approaches to maintenance. In recent years there has, for example, been increased interest in the use of marginal or non-standard materials, recycling and local materials in road maintenance. These and other innovations in road and vehicle technology are also covered in the sections on technology and standards and specifications
Further sources of information
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Updated March 2010