Idling Reduction Tax Credit Act of 2009 - Amends the Internal Revenue Code to allow a business tax credit for 50% of the cost of a qualified idling reduction device, up to $3,000. Defines "qualified idling reduction device" as any device that is: (1) used for highway transportation in combination with a trailer or semi-trailer to provide services that would otherwise require the operation of the main drive engine while the vehicle is temporarily parked or stationary; and (2) determined by the Administrator of the Environmental Protection Agency (EPA) to reduce long-duration idling.