This bill establishes a new program for urbanized area formula grants to significantly improve public transportation services and bolster safety and security. It authorizes the Secretary to provide grants for operating costs that enhance service quality, frequency, or geographic availability, and for planning service adjustments. The grants also support capital projects or operating expenses to increase public transportation system security, including personnel, and fund capital projects for safety risk mitigations identified by safety committees. Funds will be apportioned to urbanized areas based on their operating expenses, supplementing existing transportation apportionments. Recipients must certify they will use funds to increase or support total vehicle revenue service and maintain non-Federal operating and security expense levels. This operating assistance is exempt from inclusion in certain transportation improvement plans, and up to 10 percent of existing apportionments can be redirected to these new eligible activities; grants for operating expenses will cover 80 percent of the net project cost, with additional local matching funds permitted, and prohibit using certain assistance to transition fixed-route service to third-party on-demand providers.