National Capital Transportation Amendments of 1979

National Capital Transportation Amendments of 1979 - Amends the National Capital Transportation Act of 1969 to authorize the Secretary of Transportation to make additional contributions to the Washington Metropolitan Area Transit Authority to partially finance the cost of construction of the Adopted, Regional System.

Imposes limitations and conditions upon the use of such contributions.

Authorizes appropriations to carry out the purposes of this Act.

Eliminates the authorizations ceiling for both Federal and District of Columbia contributions to the System.

Requires the Transit Authority to establish a sinking fund for the accumulation of assets for payment of principal and interest on bonds issued by the Transit Authority. Establishes the percentage of contributions to be made by the Secretary and the local participating governments to this fund.

Authorizes additional appropriations for use by the Secretary to make additional contributions to meet the operating and maintenance costs of the rapid rail system of the Transit Authority.

Prohibits the Secretary from making contributions for construction, operation, or maintenance of such system unless the local participating governments have provided for a dedicated source of revenue sufficient to meet that part of the system's operation and maintenance costs that is in excess of the revenues received from the operation of such system together with any amount contributed by the Secretary.