Our Transportation segment operations generally consist of fee-based activities associated with transporting crude oil and NGL on pipelines, gathering systems, trucks and barges.

Revenue

Transportation revenue is generated through a combination of tariffs, third-party pipeline capacity agreements and other transportation fees. The Transportation segment also includes equity earnings from our investments in the Eagle Ford, White Cliffs, BridgeTex, Butte and Frontier pipeline systems as well as Settoon Towing, in which Plains owns non-controlling interests ranging from 22% to 50%.

Assets

As of December 31, 2015, Plains employed a variety of owned or leased long-term physical assets throughout the United States and Canada in the transportation segment, including approximately:

18,000+ miles of active crude oil and NGL pipelines and gathering systems
30 million barrels of active, above-ground tank capacity used primarily to facilitate pipeline throughput
142 transport and storage barges and 64 transport tugs through our interest in Settoon Towing
830 trailers (primarily in Canada)