To modify requirements under the emergency relief program under title 23, United States Code, with respect to projects for repair or reconstruction in response to damage caused by Hurricane Katrina.

Authorizes the Secretary of Transportation to obligate more than $100 million in a state for a fiscal year under the emergency relief program for projects for the repair or reconstruction of highways, roads, and trails in response to damage caused by Hurricane Katrina. (Effectively, modifies the $100 million limit that may be obligated from such program in any fiscal year for such projects). Sets the federal share of project costs at 100%. Authorizes appropriations in the amount of $2.9 billion for the emergency relief program.