Transportation and national parks are intimately linked. The inherent complexities of this intersection demand a systematic and informed management approach that extends beyond park boundaries, considers how transportation affects the quality of the visitor experience, and capitalizes on the ways in which transportation can contribute to the sustainability of parks and outdoor recreation. In this volume, twenty-one essays investigate the multiple relationships between transportation and national parks. The final chapter synthesizes this material into a series of principles to help guide sustainable transportation in the national parks.