23 May

Map of the Week: Illegal Ghost Roads

By Chiara Ryals

Networks of illegally-built roads, known as ‘ghost roads’, are proliferating across tropical forests and flying under the radar of governance. Usually built for the purpose of logging, poaching, or mining, these roads pose a severe threat to tropical forests. Networks are concentrated in hotspots of biodiversity and are often a precursor to environmental destruction. As these roads do not appear on official maps, they can escape environmental governance, driving deforestation and compromising protected areas. Forests across Indonesia, Malaysia, and Papua New Guinea are under particular threat of destruction from large-scale palm oil operations.

A recent study published in Nature mapped an area in the Asia-Pacific tropical region to illustrate the abundance of these illegal roads by comparing data from leading global road datasets and roads manually mapped from satellite imagery. In a research effort requiring 7,000 hours of work from trained volunteers, the team found that the true density of roads is severely underestimated by official sources. Lacking accurate information on human activities poses challenges to conservation efforts, creating blind spots in zoning and law enforcement and leaving extractive activities left unmonitored. Research has shown that road establishment typically precedes drastic spikes in deforestation. 

Applying strict legal protections to the land would seem to be a clear solution, however, even protected areas are not immune to the ghost road phenomenon. The same study found that roads cause similar rates of deforestation inside protected areas as outside of them. Once road density was accounted for, protected land only slightly reduced forest loss. The findings indicate that protected areas can effectively prevent deforestation only if they prevent road construction.

Similar patterns of ghost roads appear in other parts of the world threatened by deforestation like the Amazon and Congo Basins. Governments simply do not have the capacity to oversee millions of acres of forest to monitor illegal road-building. To keep up with the rapid expansion of ghost roads, AI-based road-mapping systems could be vital in monitoring these informal networks on a global scale. Methods are being developed for automated road-monitoring technologies using satellite imagery, showing promise in tackling one of the greatest threats to the world’s forests.



Ghost roads and the destruction of Asia-Pacific tropical forests

Unseen and unregulated: ‘Ghost’ roads carve up Asia-Pacific tropical forests