A bill to amend title 49, United States Code, to allow for additional transportation assistance grants.

Expands the urbanized area formula grants program to include public transit projects in urbanized areas with specified population ranges if the state or regional authority that provides public transportation for the area operates less than 100 buses in fixed-route service in the area during peak service hours. Separates population categories by graduated increases of 200,000, starting with between 200,000 and 400,000, and capping at a minimum of 1 million.

Establishes certain grant use limits for the operating costs of public transportation equipment and facilities in such projects, beginning with 50% of grant funds for certain activities and declining gradually to 30% for certain other activities.

Revises grant eligibility requirements for FY2010-FY2015 for such projects in urbanized areas with a population of at least 200,000.

Authorizes the Secretary of Transportation, during FY2010-FY2015, to award an additional grant to a designated recipient for the operating cost of public transportation equipment and facilities under this Act if the recipient: (1) was awarded a grant under the Transit Investments for Greenhouse Gas and Energy Reduction (TIGGER) program; and (2) demonstrates that it has achieved specified energy savings and total greenhouse gas emission reduction as a result of a TIGGER grant project.