Since transportation can produce significant benefits but creates many negative externalities, appropriate policies can be devised to maximize benefits and minimize inconveniences. The allocation, design, and construction of transport infrastructure and services must be subject to careful planning, both by public and private agencies. A distinction must be drawn between policy and planning since the former usually relates the strategies and goals while the latter refers to concrete actions. Policies and planning are constantly changing because they both must reflect the fundamental changes in society and contemporary issues and problems. For instance, the changing orientation of public policy led to deregulation in many transport sectors. Transport safety and security have come to the forefront among the core policy issues. Natural and anthropogenic disruptions are also challenges in transport planning.