**5.2 Energy efficiency for high-speed rail**

Freight railways deserve a lot of attention as they require about 90% of the energy of domestic rail transport. In 2011, the American Public Transportation Association (APTA) cited some UIC data in a report stating that the high-speed trains achieved about 106 mi (170 km) per kWh of energy. In comparison, planes only get 13 mi (21 km) and cars 34 mi (55 km) per kWh [35]. High-speed rails (HSR) and maglev (magnetic levitation) systems have many advantages over conventional rail, highway, and air, especially in terms of air quality and sustainability. CO2 emissions from HSR operations are significantly lower (0.1–0.3 lb of CO2/passengermile or 0.03–0.08 kg/passenger-km) than other modes of transport such as aircraft (0.6 lb./p-mi or 0.17 kg/pkm) or cars (0.5 lb/p-mi or 0.14 kg/pkm). An up-to-date life cycle analysis of HSR versus traditional rail, air, and highway modes found that system-wide comparisons of rail infrastructure construction and operation, high load and occupancy factors, maintenance and fuel, and clean electricity must be supplied with renewable energies (instead of, e.g., coal-fired power stations) [34].
