Alternative Routes for a Proposed Nigerian Superhighway to Limit Damage to Rare Ecosystems and Wildlife

The Cross River State Government in Nigeria is proposing to construct a “Cross River Superhighway” that would bisectcritical remaining areas of tropical rainforestin south eastern Nigeria. We offer and evaluate two alternativeroutes to the superhighway that would be less damaging to forests, protected areas, and biological diversity. The first alternativewe identified avoids intact forests entirely while seeking to benefit agriculture and existing settlements. The second alternativealso avoids intact forests while incorporating existing paved and unpaved roadsto limit construction costs. As currently proposed, the superhighway would be 260 km long, would intersect 115 km of intact forests or protected areas, and would cost an estimated ∼US$2.5 billion to construct. AlternativeRoutes 1 and 2 are only slightly longer (∼290 and ∼353 km, respectively) and have markedly lower estimated construction costs (∼US$0.92 billion). Furthermore, the alternativeroutes would have negligible impacts on forests and...