Transportation Trust Funds Off Budget Act of 1990

Transportation Trust Funds Off Budget Act of 1990 - Prohibits the receipts and disbursements of the Highway Trust Fund (for both the Federal Aid Highway program and the Mass Transit Account) and the Airport and Airway Trust Fund which are allocable to the transportation-related operations of such Funds from being included in either the Federal budget as submitted by the President, or in the congressional budget.

Exempts such Trust funds from any general statutory budget limitation.

Amends the Airport and Airway Improvement Act of 1982 to require the Secretary of Transportation (the Secretary) to estimate: (1) the amount of unfunded aviation authorizations at the close of the next fiscal year; and (2) the net aviation receipts for the 24-month period beginning at the close of such fiscal year. Prescribes adjustment procedures for certain unfunded aviation authorizations, and for aviation apportionments. Requires the Secretary to report such estimates to specified congressional committees.

Amends the Balanced Budget and Emergency Deficit Control Act of 1985 (Gramm-Rudman-Hollings Act) to exempt specified Airport and Airway Trust Fund and Highway Trust Fund activities from any sequestration order issued under a certain section of the Act.

Amends the Congressional Budget and Impoundment Control Act of 1974 to: (1) exclude receipts and disbursements allocable to transportation-related operations of the Funds in calculating the Federal budget deficit; and (2) prohibit the Congress from considering specified changes to such Funds.