Invest in American Railroads Act This bill revises and expands the Railroad Rehabilitation and Improvement Financing program of the Department of Transportation (DOT). Specifically, the bill authorizes DOT to pay certain credit risk premiums for loans or loan guarantees; requires DOT to set aside at least $100 million for passenger rail projects in a given fiscal year; directs DOT to provide loans and loan guarantees to private entities with controlling ownership in one or more freight railroads other than Class I carriers; expands eligibility under the loan program to include reimbursement of planning, permitting, and design expenses related to acquiring, improving, or rehabilitating intermodal or rail equipment or facilities; sets forth collateral and appraisal standards under the program; and allows loan repayment terms to be extended up to 50 years after the date of substantial completion of a project, or the estimated useful life of the rail equipment or facilities to be acquired, rehabilitated, improved, developed, or established.