This bill establishes a new competitive grant program to provide capital assistance for the maintenance, replacement, and rehabilitation of commuter rail bridges . The program authorizes $1,500,000,000 for each of fiscal years 2027 through 2031, aiming to improve the safety and reliability of critical rail infrastructure by funding eligible capital costs for operators of public transportation systems. The Secretary of Transportation will solicit applications on a competitive basis, with eligible costs limited to the net capital costs attributable to the project. A bridge access agreement is required for bridges not owned by the applicant, and grants will be awarded within specific timelines after solicitation. In evaluating applications, the Secretary will consider the size of the commuter rail system , the applicant's existing funding, and the age and condition of the commuter rail bridge , prioritizing projects identified in transit asset management plans.