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.