Roads help connect our world, however without carefully thought through plans a road can split one endangered but viable population of a species into 2 unconnected populations that are likely to disappear over the long term.
Genetic studies have shown that only one bear has managed to cross between these two Spanish bear populations. While there are only 3 major roads, there are plenty of large areas unfriendly to bears crossing through. What should put this in context, is that one bear has also managed to cross France unaided to join this population.
