Although the majority of articulated buses utilise diesel engines for their motive power, a number of operators (primarily outside North America and by LACMTA) have adopted compressed natural gas (CNG) power in order to reduce pollution. Many other transit authorities in the United States and Canada are adopting articulated buses that are diesel-electric hybrids, such as the New Flyer DE60LF. There are also articulated trolleybuses, which use catenary cables to power electric traction motors.