Safe and Competitive Trucking Act of 1991

Safe and Competitive Trucking Act of 1991 - Amends Federal law to prohibit States from regulating any of the following: (1) intrastate rates, routes, or services of any interstate motor carrier, interstate motor private carrier, or interstate broker which provides intrastate transportation of property, including express packages; or (2) the leasing, rental, or other sourcing of commercial drivers and motor vehicles by interstate motor carriers of property operating in intrastate commerce.

Prohibits States from requiring interstate motor carriers, interstate motor private carriers, or interstate brokers of property to prove the lawfulness of interstate transportation activities performed under this Act or regulations issued by the Interstate Commerce Commission. Prohibits States from requiring such carrier or broker to: (1) file and maintain any certificate or permit issued by the Commission; (2) register motor vehicles operated under a certificate or permit issued by such Commission; (3) display on any vehicle a decal, stamp, cab card, or other identification evidencing the lawfulness of such transportation activity; or (4) pay a fee or tax with respect to such activities.

Authorizes States to assess a tax or fee on motor carriers operating vehicles registered in another State only if: (1) the tax or fee is apportioned based on miles driven in the State or on some other equitable measure of such carrier's or vehicle's contact with such State; (2) the tax or fee does not discriminate against interstate commerce; (3) the tax or fee is related to the services provided to the carrier or vehicle; and (4) the activity with respect to which the tax or fee is being assessed has a substantial nexus with the State.

Authorizes a State to require an interstate motor carrier to register vehicles the carrier intends to operate within the State and collect a registration tax or fee.

Authorizes States to require interstate motor carriers to report the fuel used by its vehicles within such State and to pay a related tax or fee. Prohibits any State from requiring registration or fuel use reports or imposing related taxes or fees on or after September 30, 1994 and 1995, respectively, unless it is a member of the International Registration Plan or the International Fuel Tax Agreement.

Prohibits a State or local government from assessing a tax or fee after September 30, 1994, on a motor carrier if the carrier's only business activity within the State is: (1) the delivery or pickup of property; (2) the use of streets or roads; (3) the solicitation, sale, or advertising of transportation services by a motor carrier not domiciled in such State; or (4) to transport fully or partially loaded or empty vehicles through the State.

Prohibits a State, under specified conditions, from imposing a net worth tax on property used in interstate commerce.