This standard describes methods for the optimization of energy use of transport modes. It is applicable to the different modes of transport (road, rail, marine and aviation) as well as the different ranges (short and long distance) and the type of transport service (goods and people principally). This part of the standard covers every situation in which a displacement is made, no matter who the operator is (a public or private company or whether the operator is exclusively dedicated to transport or not). The process addresses both the optimization of energy use within each mode of transport and the selection of the best mode of transport for each situation. In the latter case, the conclusions drawn by the energy audit may influence decisions on infrastructure investments. This part includes additional requirements to be considered in energy audits with respect to transport and supplements the general energy audit requirements specified in DIN EN 16247-1. Requirements regarding the competence of energy auditors are covered in DIN EN 16247-5 "Energy audits - Part 5: Competence of energy auditors". The committee responsible for this standard is Working Committee NA 172-00-09 AA "Energieeffizienz und Energiemanagement" ("Energy efficiency and energy management") at DIN.