Rail Infrastructure Development and Expansion Act for the 21st Century

Rail Infrastructure Development and Expansion Act for the 21st Century - (Sec. 2) Amends Federal transportation law known as the Swift Rail Development Act (or the Swift Act) to make corridor development activities (including the acquisition of locomotives, rolling stock, track, and signal equipment) eligible for Federal assistance. Authorizes appropriations for FY 2004 through 2011.

(Sec. 3) Amends specified Federal law to change from discretionary to mandatory the Secretary's authority to provide direct loans and loan guarantees for rail rehabilitation and improvement projects to State and local governments, interstate compacts, government sponsored authorities and corporations, railroads, and joint ventures that include at least one railroad.

Extends the meaning of railroad, for rail rehabilitation and infrastructure financing (RRIF) program purposes, to include modern high-speed ground transportation technology such as magnetic levitation.

Increases from $3.5 billion to $35 billion the aggregate unpaid principal amounts of obligations under direct loans and loan guarantees for the RRIF program at any one time. Increases from $1 million to $7 million the set-aside for projects primarily benefiting non-Class I freight railroads. Prohibits the Secretary from establishing any limit on the amount of one loan or loan guarantee issued under the program.

Revises requirements for cohorts of loans, allowing inclusion of loans and loan guarantees.

Prohibits the Secretary from requiring a direct loan or loan guarantee applicant to provide collateral, or from having previously sought financial assistance from another source. Requires the Secretary to require such applicants to apply to their projects certain prevailing wage, health and safety, and employee protection labor standards.

Requires the Secretary to approve or disapprove an application within 90 days after its submission.

Prohibits the Secretary from assessing fees, including user fees, or charges in connection with a direct loan or loan guarantee.

Directs the Secretary to make publicly available and to publish on the Department's website the substantive criteria and standards used in rendering a decision to approve or disapprove an application.