Roads make it possible to bring goods to market, to get to the office, to log a forest, to hunt its wildlife. Without roads, human society as we know it could not exist. However, to build roads, trees must be cleared and swamps drained, shrinking valuable wildlife habitat and fragmenting populations in the process. A new study, published today in Nature, unveils an innovative map that defines which areas of the world would best be used to build roads – and which should be left alone. Scientists estimate more than 25 million kilometers of new roads will be built worldwide by 2050, representing a 60 percent increase over 2010 numbers. Many of these are slated for environmentally valuable places with high numbers of unique species and pristine forest, such as the Amazon Basin.