Data Quality and Verification

1. Data Quality and Verification Office of Highway Policy Information Federal Highway Administration

2. Why Verify • Verification versus Reviews • MF reviews look at process • Verification looks at specific numbers • Old system is hand-entry of the data • Nobody’s perfect • Motor Fuels team checks and re-checks • Errors still possible

3. Correspondence • Verification memo • Dated: • Response due April 15 • Virtually assured data will change • Second round • If no changes in the first round – FYI • If changes in the first round – re-check

4. How to evaluate • Compare State 551M monthly to the MF-33GA (gas and gasohol) and the MF-33SF (diesel and other special fuels) • Sum all the months in the year and check against the MF-21 • Gasoline Total Consumption column • Special Fuel Private and Commercial Highway Use column • Note – there are reasons these don’t always match

5. Table MF-21- Motor Fuel Use • Summary of the FHWA annual analysis • Draft attribution data • Available for review and correction • Becomes the MF-27 (finalized) • As MF-27, used to attribute federal highway revenue to the States

6. MF-21: A Closer Look - I • Starting point: two-thirds over from the left • Special fuels column • Data taken from State data • Removed all non-highway gallons • That’s it for special fuels • Gasoline • Remember: gasoline/gasohol combined • Start at column Total Consumption: agrees with total on MF-33GA

7. MF-21: A Closer Look - II • Next column to the left: Losses • Depends on State legislation • None • Flat percent losses • Actual losses • Complicated combinations • Limited to one percent of total consumption plus actual losses • New procedures in place

8. MF-21: A Closer Look - III • Non-highway Use • Two non-highway types • Private and Commercial • Public • Two treatments • P&C either State or model data • Public is all model results • Breakdown by P&C type in Table MF-24

9. MF-21: A Closer Look - IV • Public on-highway use • Two types • Federal civilian use • State, County, Municipal, and Native American government use • All data generated from FHWA models Note: Total Highway Use column is combined gasoline\gasohol used in attribution

10. Summary • Verification: • Is different than Process Review • Final State data for attribution • Should not substitute for checking the data • Month-by-month • With future techniques

11. Modeling Data • Why FHWA models data • Consistency among States • Data not otherwise available • Model off-highway gasoline • P&C gasoline off-highway • Public gasoline off-highway • Relatively small impact

12. Modeling Data • Gasohol Model • Relatively large impact • Why an issue • Federal/State definition differences • States don’t report by federal definition • Attribution impact • Federal revenue • Incentives

13. Modeling Gasohol • How the current model works • IRS reports total gasohol revenue • States providing reasonably good gasohol data are allocated their share of gallons derived from IRS data • States with no gasohol are allocated zero gallons of gasohol • States not in either of these categories are allocated the remaining gallons derived from

14. Modeling Gasohol • Regression analysis • Dependent variable: number of ethanol gallons consumed • Independent variables: • Ethanol plant proximity • Producer’s incentive amount • VMT in State non-attainment areas proportionate to State VMT • Blender’s incentive amount • Total gasoline consumed in the State

15. Modeling Gasohol Sum the estimated amounts derived from the regression calculation • Derive each estimated amount’s percentage of the total estimated • Multiply these percentages by the IRS remaining control total • Derive the distribution for each State’s three levels of gasohol

16. Modeling Gasohol • Model issues • Over emphasizes proximity to gasohol production • Conversion from MTBE to ethanol will spread gasohol use • Model needs improvements

17. Modeling Gasohol Summary • Significant impacts • State data necessary but not sufficient • Needs improvements before re-authorization