Torrential rain, as well as severe droughts and other disasters, cause decisive damage to infrastructure. Faced with the climate challenge, road construction is having to be rethought.
The link between global warming and natural disasters and catastrophes is well known, especially those related to rising temperatures and sea levels. Floods, fires caused by heatwaves, more intense storms, more aggressive hurricanes… are some examples. The number of climate-related disasters has tripled in the last 30 years, according to data from Oxfam Intermón. And let us remember that one of the Sustainable Development Goals—the thirteenth—is to “take urgent action to combat climate change and its impacts”.
But anthropogenic (that is, human-caused) climate change brings further consequences. Let us start with a fact that affects our sector, roadside assistance: the European Commission’s Green Paper of November 2000 stated that, at the end of the 1990s, energy consumption by transport accounted for 28 % of emissions of carbon dioxide, which causes the greenhouse effect.
The responsibility of the road sector in general, and the influence of road transport as a sector whose emissions had been growing over the previous decade, was starting to cause concern in 2010. At that time Spain was already exceeding the quota allocated under the Kyoto Protocol: an increase of 15 % on our 1990 baseline emissions, which in 2010 stood 50 % higher.
In 2012, a report by the European Commission’s Joint Research Centre (JCR) warned that new strategies for road design and maintenance needed to be developed. Owing to extreme weather events, the deterioration of the road network could seriously affect traffic. It could even increase the risk of accidents.
The Spanish road network: a UPM study
It is no surprise that La Vanguardia recently reported here on a study by the Universidad Politécnica de Madrid (UPM)—specifically its Transport Research Centre—which has examined the Spanish road and rail networks in relation to this issue. What influence would climate change have on our roads between 2045 and 2055?
According to the Politécnica study, average climate conditions are changing, so the functionality of transport infrastructure could be compromised, says Emilio Ortega, a researcher involved in the work. That said, the study, which analysed 396 road sections, produced results that are not very negative in the Spanish case (7 % of the network affected), at least on critical routes.
Researcher Belén Martín Ramos has likewise explained that phenomena such as asphalt softening “would not occur on the sections that contribute most to overall accessibility”. However, we will not escape erosion, landslides and flooding on adjacent land… which should be tackled with proper maintenance.
Engineering and sustainability
In a road project, a rainfall IDF (Intensity-Duration-Frequency) curve is vital, since it translates the behaviour of rainfall in a given place over a specific period. Engineering takes this tool very much into account when planning a project. It is also an indicator that changes over time, meaning it has to be updated.
Innovation is essential. The A2 motorway, between Guadalajara and Alcolea del Pinar, has become one of those smart roads capable of predicting whether it will rain more in three decades’ time, or how long heatwaves would last in 2098. There are other similar experiments in Europe, taking into account each country’s climate and the specific problems of each territory.
Furthermore, it should be noted that investment in paving and rehabilitating a road could prevent CO2 emissions from the vehicles using it. This is the position of organisations such as the European Asphalt Pavement Association, which has presented a report to this effect to the EU Parliament.