This journal article investigates transportation policies that help conserve energy and reduce pollution emissions. Some policies, called cleaner vehicle strategies in this article, reduce emission rates per vehicle-kilometer. Others, called mobility management (also called transportation demand management) strategies, reduce total vehicle travel. Some studies conclude that cleaner vehicle strategies are generally more cost effective and beneficial, while others favor mobility management strategies. Analyses that favor clean vehicle strategies tend to overlook or undervalue some significant impacts, including cleaner vehicle rebound effects and mobility management co-benefits. More comprehensive analysis tends to favor mobility management. The article investigates these issues and provides specific recommendations for comprehensive evaluation.