Revises positive train control systems implementation requirements for Class I railroad carriers that regularly provide intercity or commuter rail passenger transportation over their main lines. Requires the Secretary of Transportation to afford such carriers an opportunity to revise their plans as lines are added or removed.
Prohibits the Secretary from disapproving a carrier's plan on the grounds that it does not cover a line over which intercity rail or commuter rail passenger transportation will not be provided, nor will poison- or toxic-by-inhalation hazardous materials be transported, on or after December 31, 2015.
Requires a certain report by the Secretary to Congress to include the ability of such carriers to meet the December 31, 2015, deadline for implementation of positive train control systems.