Notes and Sources

7.  U.S. Department of Transportation, National Highway Traffic Safety Administration, “Summary of Fuel Economy Performance,” NHTSA-2007-28040-0001 (Washington, DC, March 2007), web site www.regulations.gov/fdmspublic/component/main?main= DocumentDetail&o=09000064802ad392. 

8.  U.S. Department of Transportation, National Highway Traffic Safety Administration, 49 CFR Parts 523, 531, 533, 534, 536, and 537 [Docket No. NHTSA-2008-0089] RIN 2127-AK29, Notice of Proposed Rulemaking: Average Fuel Economy Standards Passenger Cars and Light Trucks Model Years 2011-2015 (Washington, DC, April 2008), pp. 14-15, web site www.nhtsa.dot.gov/portal/site/nhtsa/menuitem. 43ac99aefa80569eea57529cdba046a0/. 

9.  A vehicle’s footprint is defined as the wheelbase (the distance from the center of the front axle to the center of the rear axle) times the average track width (the distance between the center lines of the tires) of the vehicle in square feet. 

10.  U.S. Department of Transportation, National Highway Traffic Safety Administration, Preliminary Regulatory Impact Analysis: Corporate Average Fuel Economy for MY 2011-2015 Passenger Cars and Light Trucks (Washington, DC, April 2008), pp. 374-375, web site www.nhtsa.gov/staticfiles/DOT/NHTSA/ Rulemaking/Rules/Associated%20Files/CAFE_2008_ PRIA.pdf.