Existing guidelines and documentation related to low volume roads and rural transport, such as the TRL Overseas Road Note series and the South African Technical Recommendations for Highways (TRH series) which are commonly used by practitioners in Sub Saharan Africa and, to a lesser extent, Asia, are, in many cases, outdated and do not reflect recent research findings. ReCAP therefore initiated the drafting of a series Rural Road Notes (RRNs) to fully disseminate collated research outputs related to rural access in terms of advice and guidance from a range of sources (both inside and outside of ReCAP), linked to the Sustainable Development Goals (SDGs).
A first in the series, the Rural Road Note entitled 'A Guide on the Application of Pavement Design Methods for Low Volume Rural Roads' was compiled by TRL Ltd. and is intended to provide guidance on key considerations for the use of various pavement design methods for low volume roads.The field of application ranges from earth roads through gravel surfacing to the various unbound, natural stone, bituminous, cement-based and clay brick surfacing and pavement layers. The RRN compiles the lessons learnt from the design, construction, supervision and monitoring of a range of pavement and surfacing types investigated in several countries.
The specific objectives included:
- Outlining all available methods that can be used for pavement design of LVRRs;
- Demonstrating the limitations of each design method including the environment in which the methods are most suitable for application;
- Providing procedural guidance for application of the pavement design methods.
Methodology and Phasing
The project was guided by a Stakeholder Working Group (SWG) comprising eight members to assist with development of the RRN. The main duties of the SWG were to provide technical advice and recommendations for appropriate structure, layout and content of the RRN, propose any documents that may contribute to the development of the RRN, review the draft RRN, attend review meetings, and assist in resolving any technical matters. The project was delivered in two phases. Phase 1 involved mainly scoping of the RRN. This was completed in December 2019. Phase 2 focuses on the development of the RRN, its review, its dissemination through training of users, its launch and providing printed copies to key stakeholders.
Beneficiaries and Target Audience
This Rural Road Note is aimed at engineers, road managers and others involved in the planning and design of low volume rural roads in developing and emerging regions in tropical and sub-tropical climates.
Field of application
Over the past two decades, significant progress has been made in research on suitable materials for low volume roads. It has been found that materials considered unsuitable for use on high volume roads have been found fit-for-purpose and suitable for use in low volume roads and specifications for their use have been developed. The materials are now referred to as standard materials for low volume roads.
This approach is crucial in the development of affordable and sustainable rural road infrastructure. Currently there are on-going ReCAP-supported research trials in a number of countries on long-term pavement performance in order to refine country specifications. Data from these trials are important for verification and local uptake of the various empirically developed pavement design methods.
Project Resources and Reports
Rural Road Note, Inception Report, June 2019
Rural Road Note, Scoping Report, September 2019
Rural Road Note 01: A Guide on the Application of Pavement Design Methods for Low Volume Rural Roads, July 2020
Note sur les Routes Rurales 01: Guide sur l'application des méthodes de conception des chaussées pour les routes rurales à faible volume
Media files (YouTube)
A podcast prepared by TRL is available on YouTube and provides you with an overview of the content and key insights of the RRN.
Training of Trainers (ToT) recorded presentations are grouped in a playlist on YouTube, which can be accessed here. The individual modules can be accessed by clicking on their title from the list below:
- Module 1 Introduction to the Rural Road Note 01
- Module 2 Drainage and Climate Resilience
- Module 3 Pavement Design Methods
- Module 4 Materials Surfacings Economics and Ancillary Factors Part A
- Module 4 Materials Surfacings Economics and Ancillary Factors Part B
- Module 6 Exercises and Solutions
- Module 7 Questions, Answers and Clarifications
Project Team details