A bill to amend the Regional Rail Reorganization Act of 1973 to protect branch line rail service.

Authorizes and directs the Consolidated Rail Corporation, pursuant to the Regional Rail Reorganization Act, to establish and clearly define branch line management functions, explicitly providing for the operation and marketing of rail branch line services for branch lines acquired and operated by the Corporation.

Increases the Federal share of rail service assistance funds authorized for any project pursuant to this Act to 100 percent of the cost during the first year; 90 percent during the second and third years; 80 percent during the fourth year; and 70 percent during the fifth year.

Expands the provisions for eligibility for rail service assistance funds (formerly "rail service continuation subsidies"). States that rail freight services shall be eligible for such funds if they are: (1) rail services which are not to be continued under the final system plan; (2) rail services which have been substantially aided or operated by a State agency or other public body; or (3) specified abandoned rail services.

Provides funds to States for railroad planning purposes.

Requires recipients of funds under this Act to maintain records to provide an accounting of such funds. Authorizes the Secretary and the Comptroller General to audit such records.

Authorizes the appropriation of funds to carry out the purposes of this section for each of the five fiscal years including and following the effective date of the final system plan.

Directs the Consolidated Rail Corporation, or the most appropriate railroad, to acquire and operate rail lines which had been operated under rail service continuation subsidies; and which have revenues equal to or in excess of avoidable costs plus return on investment for two sequential years.