, That when evaluating applications for assistance, the Secretary shall give priority to transit agencies with the largest revenue loss as a percentage of their operating expenses: Provided further , That if applications for assistance do not exceed available funds, the Secretary shall reserve the remaining amounts for grantees to prevent, prepare for, and respond to coronavirus and shall accept applications on a rolling basis: Provided further , That if amounts made available under this heading in this Act remain unobligated on December 31, 2021, such amounts shall be available for any purpose eligible under section 5324 of title 49, United States Code: Provided further , That the provision of funds under this section shall not affect the ability of any other agency of the Government, including the Federal Emergency Management Agency, or State agency, a local governmental entity, organization, or person, to provide any other funds otherwise authorized by law: Provided further , That notwithstanding subsection (a)(1) or (b) of section 5307 of title 49, United States Code, subsection (a)(1) of section 5324 of such title, or any provision of chapter 53 of title 49, funds provided under this heading in this Act are available for the operating expenses of transit agencies related to the response to a coronavirus public health emergency, including, beginning on January 20, 2020, reimbursement for operating costs to maintain service and lost revenue due to the coronavirus public health emergency, including the purchase of personal protective equipment, and paying the administrative leave of operations or contractor personnel due to reductions in service: Provided further , That to the maximum extent possible, funds made available under this heading in this Act and in title XII of division B of the CARES Act ( Public Law 116–136 ) shall be directed to payroll and public transit service, unless the recipient certifies to the Secretary they have not furloughed any employees: Provided further , That such operating