Roads are a key asset for Africa. They connect villages to economic centers, people to hospitals, children to schools and goods to markets facilitating trade. This report examines the implications of climate change for Africa’s road connectivity, and practical steps that can be taken now to minimize the associated risks. The scope of the report includes 2.8 million km of roads throughout Sub-Saharan Africa, with a special focus on new road construction outlined in the Programme for Infrastructure Development in Africa (PIDA), an African Union facilitated initiative to enhance trans-boundary connectivity through the continent.
The main conclusions of the report are:
- adequate road maintenance is the most critical and most efficient way of reducing the impact of a changing climate on the road system. In the absence of an adequate maintenance regime, the damage caused by climactic events is exacerbated. The uncertainty related to climate change further reinforces this dynamic. Thus, maintenance of pavements and sealing activities; regular maintenance of bridges, culverts and drainage structures to ensure they are functional and not obstructed; maintenance and improvement of slope protection works; and systematic assessments to identify and incrementally address vulnerable and critical road sections are the first defense to climate risks
- simply ignoring climate change is not an option. The report shows that climate change is likely to lead to a shortening of roads rehabilitation life-cycle, which, in addition to maintenance, usually entails resurfacing every 20 years. The shortened life-cycle is likely to lead to steep increases in maintenance and periodic rehabilitation costs
- proactive adaptation in response to temperature increase is a no regret option. Modifying the design in response to an anticipated higher temperature is a low or no-regret option for paved roads in virtually all countries and the vast majority of climate scenarios, including both the PIDA transboundary corridors and the planned expansion/upgrade of the national networks. The reason is that the savings accrued over the road life cycle more than offset the higher construction costs, even if the measures are adopted now, before significant temperature increases are experienced
- the case for proactive adaptation in response to precipitation is not as clear cut, and needs to be assessed case by case. Because of the fundamental uncertainty regarding future climate, it is not possible to be as definite
on how to proactively design for precipitation. Rainfall varies all over the continent, but in several countries (e.g. Angola, Nigeria, Botswana, Togo, South Sudan, Mozambique, Benin, and Cameroon), it is clear that even moderate changes in the climate will induce significant precipitation-related disruption. In these countries, it would be appropriate to start proactively adapting the road system. In other countries, more detailed analysis is needed to identify where, when and how to invest in resilience most appropriately. Some roads in some areas may well already benefit also from pro-active adaptation - better information on the benefits of avoiding climate-related disruption can inform decisions on proactive adaptation. This report develops a methodology to evaluate the merits of proactive adaptation in the context of an uncertain future climate