Because of public feedback, two additional alternatives will now be studied as possible solutions to traffic congestion in Little Cottonwood Canyon: a new cog rail line plus a longer version of a proposed gondola that would begin in the valley below the mouth of the canyon. The cog rail — a diesel-powered train with a cogwheel on the track beneath it to provide traction on steep slopes — would cost an estimated $1.05 billion. The new version of the gondola would cost $576 million. Those will join three other options previously announced for more in-depth study.