# Policy Guidance on the Use of MOVES2010 for State Implementation Plan Development, Transportation Conformity, and Other PurposesEPA-420-B-09-046

December 2009 Transportation and Regional Programs Division Office of Transportation and Air Quality U.S. Environmental Protection Agency 

# Policy Guidance on the Use of MOVES2010 for State Implementation Plan Development, Transportation

Conformity, and Other PurposesTable of Contents

INTRODUCTION ................................................................................................................... ..................... 3

1. W HAT IS THE PURPOSE OF THIS GUIDANCE ? ...................................................................................... 3

2. W HAT IS MOVES2010 AND HOW DOES IT COMPARE TO MOBILE6.2? ............................................ 3

3. W HAT ADDITIONAL RESOURCES ARE AVAILABLE TO ASSIST IN IMPLEMENTING MOVES2010?........ 5

4. D OES THIS GUIDANCE CREATE NEW REQUIREMENTS ? ....................................................................... 5

SIP DEVELO PMENT................................................................................................................ .................. 6

5. H OW DOES THE RELEASE OF MOVES2010 AFFECT SIP S THAT HAVE ALREADY BEEN SUBMITTED

AND / OR APPROVED

, OR SIP S THAT ARE CURRENTLY UNDER DEVELOPMENT ? ................................... 6

6. W HAT EMISSIONS MODEL MUST BE USED FOR PREPARING INVENTORIES FOR SIP S FOR AREAS

DESIGNATED NONATTAINMENT FOR THE 2006 PM 2.5 NAAQS?......................................................... 7

7. W HEN EXISTING SIP S AND MOTOR VEHICLE EMISSIONS BUDGETS ARE REVISED WITH MOVES2010,

WHAT DO STATES NEED TO SUBMIT TO SHOW THAT A SIP CONTINUES TO MEET APPLICABLE

REQUIREMENTS ? .............................................................................................................................. . 7

8. H OW WILL MOVES2010 AFFECT THE NEED FOR EMISSIONS REDUCTIONS IN THE DEVELOPMENT OF

FUTURE ATTAINMENT OR MAINTENANCE SIP S ? .............................................................................. 10

9. W HAT ROLE WILL MOVES2010 PLAY IN EPA’ S N ATIONAL E MISSIONS I NVENTORY ? ................... 10

TRANSPORTATION CONFORMITY ................................................................................................... 10

10. W HEN WILL THE USE OF MOVES2010 BE REQUIRED FOR TRANSPORTATION CONFORMITY

DETERMINATIONS ?.......................................................................................................................... 10

11. U NDER WHAT CIRCUMSTANCES WILL THE MOVES2010 GRACE PERIOD BE SHORTER THAN TWO

YEARS ? .............................................................................................................................. ............. 11

12. H OW WILL THE MOVES2010 GRACE PERIOD BE IMPLEMENTED FOR REGIONAL EMISSIONS

ANALYSES ? .............................................................................................................................. ....... 12

13. H OW WILL THE MOVES2010 GRACE PERIOD BE IMPLEMENTED FOR CO, PM 10 AND PM 2.5 QUANTITATIVE HOT

- SPOT ANALYSES ? ............................................................................................ 13

14. W HAT MODEL SHOULD BE USED FOR THE FIRST TRANSPORTATION PLAN AND TIP CONFORMITY

DETERMINATIONS FOR AREAS DESIGNATED NONATTAINMENT FOR THE 2006 PM 2.5 NAAQS?........ 15

15. W HAT MODEL SHOULD BE USED FOR QUANTITATIVE PM 10 AND PM 2.5 HOT

- SPOT ANALYSES FOR

CERTAIN PROJECT

- LEVEL CONFORMITY DETERMINATIONS IN C ALIFORNIA ? ................................... 15

USING MOVES2010 FOR OTHER PURPOSES ................................................................................... 16

16. C AN MOVES2010 BE USED TO ESTIMATE GREENHOUSE GAS EMISSIONS ?...................................... 16

17. C AN MOVES2010 BE USED TO ESTIMATE MOBILE SOURCE AIR TOXICS ?........................................ 16

2I NTRODUCTION

1. What is the purpose of this guidance?

This guidance describes how and when to use the MOVES2010 emissions model for state implementation plan (SIP) development, transportation conformity determinations, and other purposes.

EPA will be publishing a Federal Register notice of availability in the near future to approve MOVES2010 for official pur poses. Upon publication of the Federal Register notice, MOVES2010 will become EPA’s approved motor vehicle emissions factor model for estimating volatile organic compounds (VOCs), nitrogen oxides (NOx), carbon monoxide (CO), direct particulate matter (PM 10 and PM 2.5 ) and other precursors from cars, trucks, buses, and motorcycles by state an d local agencies for SIP and transportation conformity purposes outside of California. EPA intends to include in the notice a twoyear grace period for using MOVES2010 for tr ansportation conformity purposes. EPA coordinated closely with the U.S. Depa rtment of Transportation (DOT) in the development of this guidance.

The same Federal Register notice approving MOVES2010 will also approve the use of the EMFAC2007 model when completing PM 2.5 and PM 10 hot-spot analyses for transportation conformity purposes in Califor nia. See Question 15 for more information about the use of EMFAC2007 for these conformity analyses.

EPA has also included information regard ing the use of MOVES2010 for estimating

mobile source air toxic and greenhouse gas emissions. A lthough there are no SIP or conformity requirements for these emissi ons, MOVES2010 is EPA’s best tool for estimating air toxic and greenhouse gas emissi ons from on-road mobile sources. See Questions 16 and 17 for further information.

The following contacts are available at EPA’ s Office of Transportation and Air Quality regarding this guidance:

 for general questions about the MOVES model, email mobile@epa.gov ;

 for SIP questions, contact R udy Kapichak at (734) 214-4574;

 for transportation conformity questions , contact Meg Patulski at (734) 214- 4842; and

 for questions about the National Emissions Inventory, contact Laurel Driver at EPA’s Office of Air Quality Planni ng and Standards at (919) 541-2859.

A copy of this policy guidance can be found at the following website: http://www.epa.gov/otaq/statere sources/transconf/policy.htm

.

2. What is MOVES2010 and how does it compare to MOBILE6.2?

MOVES2010 is a computer model designed to estimate emissions factors and emissions inventories of VOCs, NOx, CO, PM 10 , PM 2.5 and other pollutants a nd precursors for cars,

3trucks, buses, and m otorcycles. MOVES 2010 was designed to replace the previous emissions model, MOBILE6.2, which was released in 2004 (69 FR 28830). MOVES2010 replaces MOBILE6.2 as the emis sions model that EPA will maintain and

support.

MOVES2010 improves upon MOBILE6.2 in many respects. For example, MOVES2010

is based on a review of the vast amount of in-use vehicle data collected and analyzed

since the release of MOBILE 6.2, including millions of emissions measurements from light-duty vehicles. Analysis of this in-u se data has enhanced EPA’s understanding of

how on-road mobile sources c ontribute to emissions inventories ,and has also improved the agency’s understanding of the relative effectiveness of various control strategies.

MOVES2010 has a database-cente red design that allows users much greater flexibility in organizing input and output data. This stru cture also allows EPA to update emissions data incorporated in MOVES2010 mo re easily. MOVES2010 estimates PM 2.5 and PM 10 to account for speed and temperature variati ons, and models emissions at high resolution, which allows users to incorporate a much wi der array of activity data and to model emissions at the link and project level.

EPA has performed a preliminary comparis on of MOVES2010 to MOBILE6.2 using local data for several different urban counties, varying the local data used by fleet age distribution, fraction of light- and heavy-duty vehicle miles travelled (VMT), local fuel specifications, meteorology, and other input factors. Actual results will vary based on local inputs in a given area, with local variations in fleet age distribution and composition having a significant influence on the final results. In general, VOC emissions are lower when using MOVES 2010 when compared to MOBILE6.2, while both NOx and PM emissions are higher. 1

MOVES2010 includes the capability to esti mate vehicle exhaust and evaporative

emissions as well as brake wear and tire wear emissions for criteria pollutants and precursors. However, MOVES2010 does not incl ude the capability to estimate emissions

of re-entrained road dust. To estimate emissions from re-entrained road dust, practitioners should continue to use the latest approved methodologies. 2

1 For further information, please see EPA’s communicat ions materials for MOVES release on the following

website: http://www.epa.gov/otaq/m od els/moves/index.htm

. 2 See EPA’s notice of availability published in the Federal Register on May 19, 2004, 69 FR 28830-28832. Also see EPA’s memoranda: “Policy Guidance on the Use of the November 1, 2006, Updated to AP-42 for Re-entrained Road Dust for SIP Development and Transportation Conformity,” August 2, 2007; and “Policy Guidance on the Use of MOBILE6.2 and the December 2003 AP-42 Method for Re-entrained Road Dust for SIP Development and Transportation Conformity,” February 24, 2004. These documents

are available on EPA’s website at: http://www.epa.gov/otaq/stater eso urces/transconf/policy.htm

.

43. What additional resources are availabl e to assist in im plementing MOVES2010?

In addition to this guidance document, EPA has developed several documents to assist in implementing MOVES2010, including the following:

 “MOVES2010 User Guide”: This guide provid es detailed instructions for setting up and running MOVES2010. Available at http://www.epa.gov/otaq/models/moves/index.htm

.

 “Technical Guidance on the Use of MOVES2010 for Emission Inventory Preparation in State Implementation Plan s and Transportation Conformity”: This document provides guidance on appropriate i nput assumptions and sources of data

for the use of MOVES2010 in SIP submi ssions and regional emissions analyses for transportation conformity determinations. Available at http://www.epa.gov/otaq/statere sources/transconf/policy.htm

.

 “Transportation Conformity Guidance for Quantitative Hot-spot Analyses in

PM 2.5 and PM 10 Nonattainment and Maintenance Areas”: This document explains how to use MOVES2010 to complete hot-spo t analyses required for projects of local air quality concern in PM 2.5 and PM 10 nonattainment and maintenance areas. This guidance is presently under development and will be posted on the EPA’s transportation conformity policy guidance website ( http://www.epa.gov/otaq/statere sources/transconf/policy.htm ) when available. 3

Additional training materials, examples, and MOVES2010 technical information are

available at the MOVES website: http://www.epa.gov/otaq/models/moves/index.htm

.

4. Does this guidance create new requirements?

The discussion in this document is intended solely as guidance. The statutory provisions and EPA regulations described in this docum ent contain legally binding requirements. This document is not a regulation itself, nor does it change or substitute for those provisions and regulations. EP A retains the discretion to adopt approaches on a case-bycase basis that may differ from this documen t, but still comply with the statute and regulations. Any decisions regarding a partic ular SIP or conformity determination will be made based on the statute and regulations. This document may be revised periodically without public notice.

3 EPA will be making a draft available for public comment prior to finalizing this guidance.

5SIP D EVELOPMENT

5. How does the release of MOVES2010 affect SIPs that hav e already been submitted and/or approved, or SIPs that are currently under development?

In general, EPA believes that MOVES2010 should be used in ozone, CO, PM, and NO 2 SIP development as expeditiously as possibl e. The Clean Air Act requires that SIP

inventories and control measures be based on the most current information and applicable

models that are available when a SIP is developed. 4 However, it is also important to recognize the time and level of effort that states have alread y undertaken in SIP development with MOBILE6.2. States should consult with their EP A Regional Office if they have questions about how MOVES2010’s release affect s specific nonattainment or maintenance areas. Early consultation can facilitate EPA’s adequacy finding or SIP approval process. The following paragraphs articulate EPA’s policy for the use of MOVES2010 in the development of SIPs.

The release of MOVES2010 would not requir e a SIP revision solely based on the

existence of the new model. EPA believes th at the Clean Air Act does not require states that have already submitted SIPs or will submit SIPs shortly after the release of MOVES2010 to revise these SIPs simply b ecause a new motor vehicle emissions model

is now available. EPA believes that this is supported by existing EPA policies and case law [ Sierra Club v. EPA , 356 F.3d. 296, 307-08 (D.C. Cir. 2004)]. Of course, states can choose to use MOVES2010 in these SIPs, for ex ample, if it is determined that it is appropriate to update motor vehicle emi ssions budgets with the model for future conformity determinations. However, EPA does not believe that the state’s use of

MOBILE6.2 should be an obstacle to EPA approval for reasonable further progress (RFP), attainment, or maintenance SIPs that have been or will soon be submitted based on MOBILE6.2, assuming that such SIPs are otherwise approvable and significant SIP work has already occurred (e.g., attainment mo deling for an attainment SIP has already been completed with MOBILE6.2). It would be unreasonable to require the states to

revise these SIPs with MOVE S2010 since significant work has already occurred based on the latest information available at the time, and EPA intends to act on these SIPs in a timely manner.

States should use MOVES2010 where SIP developm ent is in its initia l stages or has not progressed far enough along that switching to MOVES2010 would crea te a significantly adverse impact on state resour ces. MOVES2010 should be inco rporated into these SIPs

since the emissions estimates from MOVE S2010 are based on the best information currently available.

EPA also believes it may not be reasonab le to approve a MOBILE6.2-based SIP the longer that MOVES2010 is in place and availabl e for use. Since SIPs must be based on applicable models and data inputs, EPA may not have a basis to approve a SIP developed with MOBILE6.2 significantly after MOVES 2010 becomes available. If you have

4 See Clean Air Act section 172( c)(3) and 40 CFR 51.112(a)(1).

6questions about which model should be used in your SIP, please consult with your E PA Regional Office.

Incorporating MOVES2010 into the SIP now could also assist areas in mitigating possible transportation conf ormity difficulties in the future after the MOVES2010 conformity grace period ends. New conformity analyses that are started after the grace period is over must be based on MOVE S2010 (40 CFR 93.111), so having MOVES2010- based SIP motor vehicle emissions budgets in place at that time could provide more consistency with transportation conformity determinations. See Question 10 for more information on MOVES2010 and transportati on plans and transportation improvement program (TIP) conformity.

6. What emissions model must be used for preparing inventories for SIPs for areas designated nonattainment for the 2006 PM 2.5 NAAQS?

EPA believes that MOVES2010 is the emissions model that must be used for developing

on-road mobile source inventories for the 2006 PM 2.5 NAAQS SIPs (except those in California) because it reflects th e latest available information. 5 EPA designated nonattainment areas for this NAAQS on November 13, 2009 (74 FR 58688), which should give state and local agencies ti me to incorporate MOVES2010 into SIP submissions for this NAAQS. Using MOVES2 010 to create SIP budgets may also help in the transition to using MOVES2010 for tr ansportation conformity purposes at the end of the conformity grace period (see Question 10).

7. When existing SIPs and motor vehicl e em issions budgets are revised with MOVES2010, what do states need to submit to show that a SIP continues to meet applicable requirements?

As stated in Question 5, a SIP revision would not be required solely due to the release of MOVES2010 for SIPs that have been approved, submitted, or where significant development has already occurred. However, there may be other cases where an existing

SIP is revised with MOVES2010. In addres sing these cases, EPA is applying the same principles it has in the past when motor ve hicles emissions budgets have been revised using a new emissions model. States should consult w ith their EPA Regional Office prior to submitting MOVES2010 SIP revisions. Early consultation can facilitate EPA’s adequacy finding or SIP approval process.

EPA has always required under the Clean Air Act that revisions to existing SIPs and budgets continue to meet applicable requi rements (e.g., RFP or attainment). For example, if a state revises a maintenance plan to add or delete cont rol measures, the state

needs to show in its revised SIP that mainte nance continues to be demonstrated with the new mix of control measures. Similarly, states that revise existing SIPs with

MOVES2010 must show that the SIP continues to meet applicable requirements with the new level of motor vehicle emissions calculated by the new model.

5 See Clean Air Act section 172( c)(3) and 40 CFR 51.112(a)(1).

7In addition, the transportation conform ity ru le (40 CFR 93.118(e)(4)( iv)) requires that “the motor vehicle emissions budget(s), when considered together with all other emissions sources, is consistent with app licable requirements for reasonable further progress, attainment, or maintenance (whichev er is relevant to th e given implementation plan submission).” This a nd other criteria must be satisfied before EPA can find submitted budgets adequate or approve them for use in the conformity process.

The following paragraphs describe how to meet applicable requirements for existing SIPs

that are revised with MOVES 2010, including ideas for how to streamline these revisions whenever possible.

Use of latest planning assumptions : When SIPs are revised with MOVES2010, base year, milestone year and attainment/maintenance year motor vehicle emissions inventories will need to be recalculated with the latest available planni ng assumptions. As required by Clean Air Act section 172(c )(3) and EPA’s regulation at 40 CFR 51.112(a), states must use the latest planning assumptions availabl e at the time that the SIP is developed, including but not limited to the latest info rmation for vehicle miles traveled (VMT), speeds, fleet mix, and SIP control measures. 6 Base year and histor ical year inventories must use the latest data available for those y ears. Future year proj ection inventories must

also be based on the latest data available. If planning assumptions have not changed since the original SIP was submitted, the st ate should document this in its new SIP

submission.

In addition, states must consider whether growth and control st rategy assumptions for non-motor vehicle sources (i.e., stationary, ar ea and non-road mobile sources) are still

accurate at the time that the MOVES2010 SIP revision is developed. Such assumptions include population and economic assumptions and any allowable emissions relied upon for stationary or other sour ces. If these assumptions have not changed, the state can simply re-submit the original SIP with the revised motor vehicle emissions inventories and budgets and meet the remaining requireme nts as discussed below. Otherwise, the emissions categories in the SIP that ha ve changed must be brought up to date.

Milestone, attainment or maintenance demonstration : As discussed above, SIP revisions

based on MOVES2010 must continue to show that the SIP still meets applicable requirements (e.g., attainment or maintenance) when previous motor vehicle emissions inventories are replaced with MOVES2010 inventories. The level of effort needed for this demonstration can vary depending upon how MOVES2010 affects the level of motor

vehicle emissions and whether non-motor vehicle inventories require updating. The method used to develop the original de monstration could also be a factor.

Areas can revise their motor vehicle emissions inventories and budgets using MOVES2010 without revising the entire SI P or completing additional modeling if:

6 See EPA and DOT’s joint “Guidance for the Use of Latest Planning Assumptions in Transportation Conformity Determinations,” EPA420-B-08-901 (Dec. 2008). This guidance also addresses requirements for using the latest planning assumptions in SIP development.

8(1) The SIP continue s to meet applicable requirements when the previous motor vehicle emissions inventories are repl aced with MOVES2010 base year and milestone, attainment, or maintenance year inventories; and,

(2) The state can document that the growth and control strategy assumptions for

non-motor vehicle sources continue to be valid and any minor updates do not change the overall conclusions of the SIP.

For example, consistent with EPA’s SIP mode ling guidance for various pollutants, if an ozone SIP relied on changes in emissions from the base year to an attainment or maintenance year inventory to estimate relative changes in monitored ozone levels, the first criterion could be satisfied by demonstr ating that the relative emissions reductions between the base year and the attainment or maintenance ye ar are the same or greater using MOVES2010 than they were previously. Alternatively, if an ozone attainment SIP relied on absolute model predictions for the future attainment year, then the first criterion could be satisfied by demonstr ating that the MOVES2010 estimat es are equal to or lower than the previous estimates for the future attainment year. Or, if a CO maintenance plan

relied on either a relative or absolute demons tration, the first criter ion could be satisfied by documenting that the relativ e emissions reductions betwee n the base year and the maintenance year are the same or greater using MOVES2010. In any case, if using the latest planning assumptions for emissions estim ates results in changes to other emissions categories (e.g., stationary or ar ea emissions), the demonstrat ion would apply to the entire inventory, rather than just the on-road mobile inventory.

If both of the above criteria are met, the stat e can simply re-submit the original SIP with

the revised MOVES2010 motor vehicle emissions inventories. If either criterion is not met, the emissions categories in the SIP that have changed must be brought up to date. Any changes in control strate gies, including stationary sour ce inventories, must be

factored in to both base and fu ture year inventories to dete rmine if they would indicate a nonattainment problem. However, a state woul d not necessarily have to revise a nonmotor vehicle emissions inventory category ju st to account for a re gulatory or permit change that reduces these emissions in an attainment or maintenance year relative to the existing SIP.

Regardless of the technique used, a more rigorous reassessment of the SIP’s demonstration may be necessary if a state deci des to reallocate the original SIP’s excess

emissions reductions to the motor vehicl e emissions budget as a safety margin. 7 In other words, the state will need to assess how its original demonstration is affected by using

MOVES2010 and confirm whether excess emissions exist prior to allocating them to the motor vehicle emissions budget. This assessment would need to be sufficiently detailed to permit the requantification of any excess em issions. This assessment is critical to

7 A “safety margin” is the amount by which the total projected emissions from all sources of a given pollutant are less than the total emissions that would satisfy the applicable requirement for reasonable further progress, attainment, or maintenance (40 CFR 93.101). See also 40 CFR 93.124(a) for its application.

9ensure that SIP budgets in the context of all other em issions sources continue to protect public health and meet the conformity rule’s adequacy cr iteria (40 CFR 93.118(e)).

8. How will MOVES2010 affect the need for em issions reductions in the d evelopment

of future attainment or maintenance SIPs?

The answer to this question depends upon the unique circumstances of each

nonattainment or maintenance area. The em issions comparisons depend very heavily on the pollutants of concern, the dates of con cern, and on existing local regulations, traffic patterns, fleet age, and mix of cars and trucks. In some cases, a change from MOBILE6.2 to MOVES2010 may result in increa sed emissions estimates, while in other cases it may result in decreased emissions estimates for various time periods.

Moreover, because of the complex chemistr y and meteorology involved in air pollution, the implications of changes in highway vehi cle emissions may not be clear until multiple years are examined and the new emissions levels are applied to an air quality model.

Relative differences in emissions over time from MOBILE6.2 to MOVES2010 may be as important as, or more important than, diffe rences between the two models in any one year. Therefore, MOVES2010 users should not immediately assume that increases or decreases in emissions in any single year im ply the need for more or fewer SIP control measures until those changes in emissions have been put in the complete SIP context.

An increase in emissions due to the use of MOVES2010 may affect an area’s ability to demonstrate conformity for its transportation plan and/or TIP. Areas are encouraged, through the interagency consultation process, to consider if a nd how MOVES2010 will impact their future conformity determina tions and discuss any concerns with the appropriate EPA Re gional Office.

9. What role will MOVES2010 play in EPA’s National Emissions Inventory?

The National Emissions Inventory (NEI) is updated with state, local, and tribal submissions once every three years. The cu rrent NEI under development is for the year 2008. For 2008, EPA is using the National Mob ile Inventory Model (NMIM) which runs

MOBILE6.2 for on-road emissions. EPA’ s preference is that agencies submit activity and input updates to NMIM’s National County Database , rather than emissions, in order to allow for more in-depth analysis and cons istent, integrated calculated emissions in the NEI. However, agencies may also submit emissions for the 2008 cycle generated with either MOBILE6.2 or MOVES2010 (or EMFAC2007 if in California). EPA expects to use MOVES2010 for the 2011 NEI cycle fo r states other th an California.

T RANSPORTATION C ONFORMITY

10. When will the use of MOVES2010 be re quired for tran sportation conformity

determinations?

10EPA intends to establish a two-year g race period before MOVES2010 is required for new transportation plan, TIP, and pr oject-level conformity determin ations. The effective date

of the Federal Register notice announcing the approval of the MOVES2010 model will constitute the start of the conformity grace pe riod. EPA coordinated closely with DOT in the development of this guidance. See Questions 11, 12 and 13 for details about how this grace period will be implemented.

Transportation conformity is a Clean Air Ac t requirement to ensure that federally supported highway and transit activities are c onsistent with (“conform to”) the SIP. Conformity to a SIP means that a transporta tion activity will not cau se or contribute to new air quality violations; worsen existing vi olations; or delay timel y attainment of the national ambient air quality standards or an interim milestone.

The transportation conformity rule (40 CFR Parts 51 and 93) requires that conformity analyses be based on the latest motor ve hicle emissions model approved by EPA. Section 176(c)(1) of the Clean Ai r Act states that “....[t]he determination of conformity

shall be based on the most recent estimates of emissions, and such estimates shall be determined from the most recent popul ation, employment, travel, and congestion estimates....” When EPA approves a new emissions model like MOVES2010, it establishes a grace period before the model is required to be used for conformity analyses. The conformity rule provides for a grace period for new emissions models of between 3-24 months, to be es tablished by notification in the Federal Register (40 CFR 93.111(b)(1)).

EPA has previously explained how it will determine the appropriate length of a conformity grace period (58 FR 62211):

“EPA and DOT will consider extending the grace period if the effects of

the new emissions model are so significant that previous SIP

demonstrations of what emission levels are consistent with attainment would be substantially affected. In such cases, States should have an opportunity to revise their SIPs befo re MPOs must use the model’s new

emissions factors.”

In consultation with DOT, EPA must consid er many factors when establishing a grace period for conformity determinations, incl uding the degree of change in emissions

models and the effects of the new model on the transportation planning process (40 CFR 93.111(b)(2)).

11. Under what circumstances will the MOVE S2010 grace pe riod be shorter than two years?

The Federal Register notice announcing the approval of MOVES2010 and the conformity grace period will state that th e grace period will be two years unless new motor vehicle emissions budgets become a pplicable sooner, in which case the grace

11period will end once these new MOVES2010- based approved or adequate budgets

becom e effective. The grace period will be shor ter than two years for a given pollutant if an area revises its SIP and budgets wi th MOVES2010, and such budgets become applicable for regional conformity purposes pr ior to the end of the two-year grace period. In this case, the new regional emissions anal ysis must use MOVES 2010 if the conformity

determination is based on a MOVES2010-ba sed budget. The interagency consultation process must be used to develop any SIP revision based on MOVES2010 (40 CFR 93.105(a)).

Areas that are designated nonattainment or ma intenance for multiple pollutants may rely

on both MOVES2010 and MOBILE6.2 to determin e conformity for different pollutants during the grace period. For example, if an area revises a previously submitted (but not approved) MOBILE6.2-based PM 10 SIP with MOVES2010 and EPA finds these revised MOVES2010 budgets adequate for conformity, such budgets would apply for conformity

on the effective date of the Federal Register notice announcing EPA’s adequacy finding. In this example, if an area was in nonattainment for PM 10 and ozone, the MOVES2010 grace period would end for PM 10 once EPA found the new MOVES2010-based SIP budgets adequate. However, MOBILE6.2 c ould continue to be used for ozone conformity determinations until th e end of the MOVES2010 grace period. 8 In addition, the length of the grace period for hot-spot an alyses would not be affected by an early submission of MOVES2010-based SIP budge ts. In this example, for PM 10 hot-spot analyses the two-year grace period would sti ll apply even if the grace period is shortened for regional PM 10 conformity analyses, as explained in Question 13. EPA Regional Offices should be consulted for questions re garding other situations in multi-pollutant

areas.

In addition, if an area revise s a previously approved SIP using MOVES2010, the revised MOVES2010 budgets would be used for c onformity purposes once EPA approves the MOVES2010 SIP revision, in most cases. In general, submitted SIPs cannot supersede approved budgets until they are approved. However, 40 CFR 93.118(e)(1) allows an approved budget to be replaced by an adequate budget if EPA’s approval of the initial budgets specifies that the budgets being appr oved may be replaced in the future by new adequate budgets. This flexibility has been us ed in limited situations in the past, such as during the transition from MOBILE5 to MOBILE6. In such cases, the MOVES2010- based budgets would be used for conform ity purposes once they have been found adequate, if requested by th e state in its SIP submission and specified in EPA’s SIP approval. States should consult with thei r EPA Regional Office to determine if this flexibility applies to their situation.

12. How will the MOVES2010 grace period be im plemented for regional emissions analyses?

8 In this example, such an area would use MOVES2 010 to develop a regional emissions analysis for comparison to the revised MOVES2010-based budgets (e.g., PM 10 and NOx budgets). The regional emissions analysis for ozone could be based on MOBILE6.2 for the VOC and NOx budgets in the ozone SIP for the remainder of the conformity grace period.

12During the confor mity grace period, areas s hould use the interagency consultation process to examine how MOVES2010 will impact their future transportation plan and TIP conformity determinations, including re gional emissions analyses. Areas should carefully consider whether the SIP and mo tor vehicle emissions budget(s) should be

revised with MOVES2010 or if transportation plans and TIPs should be revised before the end of the conformity grace period, sin ce doing so may be necessary to ensure conformity in the future.

Regional emissions analyses that are star ted during the grace period can use either MOBILE6.2 or MOVES2010. When the gra ce period ends, MOVES2010 will become the only approved motor vehicle emissions model for transportation conformity purposes in states outside California. In general, this means that all new conformity analyses

started after the end of the grace period must be based on M OVES2010, even if the SIP is based on MOBILE6.2. As discussed above, th e grace period for new regional emissions analyses would be shorter for a given pollutant if an area revised its SIP and budgets with MOVES2010 and such budgets were appr oved or found adequate for conformity purposes prior to the end of the two-year grace period.

The conformity rule provides some flexibility for analyses that are started before the end of the grace period. Regional emissions analys es that begin before or during the grace period may continue to rely on MOBILE6.2. The interagency consultation process

should be used if it is uncl ear if a MOBILE6.2-based analysis was begun before the end of the grace period. If you have questions about which model should be used in your conformity determination, you can also consult with your EPA Regional Office.

13. How will the MOVES2010 grace period be implemented for CO, PM 10 and PM 2.5 quantitative hot-spot analyses?

EPA intends to establish a two-year grace pe riod before MOVES2010 will be required to be used when completing new CO, PM 10 and PM 2.5 quantitative hot-spot analyses in areas outside of California. This grace peri od would begin on the effective date of the Federal Register notice announcing the rel ease of the final version of MOVES2010. EPA believes that a two-year grace period is appropriate before requiring MOVES2010 for new hot-spot analyses, due to the degree of change in the model as compared to past EPA models and the time necessary to pr epare for using MOVES2010 for project-level analyses. See Question 10 for more general information about the conformity grace period.

Sections 93.116 and 93.123 of the conformity ru le contain the requirements for when a hot-spot analysis is required for proj ect-level conformity determinations. 9 The

9 In CO nonattainment and maintenance areas, a hot-spo t analysis is required for all non-exempt projects, with quantitative hot-spot analyses being required for larger, congested intersections and other projects (40 CFR 93.123(a)(1)). In addition, the confor mity rule requires that a quantitative PM 10 or PM 2.5 hot-spot analysis be completed for certain projects of local air quality concern once EPA releases modeling guidance and announces in the Federal Register that the PM 10 and PM 2.5 quantitative hot-spot analysis requirements are in effect (40 CF R 93.123(b)). In coordination with DOT, EPA is currently preparing guidance on how to conduct quantitative PM 2.5 and PM 10 hot-spot modeling to implement this requirement

.

13conf ormity rule provides some flexibility for analyses that are star ted before the end of the grace period. A conformity determinati on for a transportation project may be based on a previous model if the analysis was be gun before or during th e grace period, and if the final environmental document for the project is issued no more than three years after

the issuance of the dr aft environmental document (40 CF R 93.111(c)). The interagency consultation process should be used if it is unclear if a previo us analysis was begun before the end of the grace period. If you have questions about which model should be used in your conformity determination, you can also consult with your EPA Regional

Office.

Implementation of grace period for CO hot-spot analyses : For CO hot-spot analyses that are started during the two-year grace period, project sponsors can choose to use either

MOBILE6.2 or MOVES2010. EPA encourages sponsors to us e the consultation process to determine which option may be most appr opriate for a given situation. Any new quantitative CO hot-spot analyses for conf ormity purposes begun after the end of the grace period must be based on MOVES2010.

Implementation of grace period for PM 10 and PM 2.5 hot-spot analyses: For PM 10 and

PM 2.5 hot-spot analyses, the conform ity rule presently requires a qualitative analysis to be performed until EPA releases guidance on how to conduct quantitative hot-spot analyses

for PM and announces in the Federal Register that such analyses are in effect (40 CFR 93.123(b)). 10 EPA stated in the preamble to th e March 10, 2006 final conformity rule that finalizing the MOVES2010 emissions model was critical before quantitative PM hotspot analyses are required, due to the limita tions of applying MOBI LE6.2 for PM at the project level. EPA also stated that today’s guidance would be used to describe the grace period for using MOVES2010 in quantitative hot -spot analyses for certain project-level conformity determinations in PM nonattainment and maintenance areas. 11

During the conformity grace period, project spon sors can continue to conduct qualitative

PM 10 and PM 2.5 hot-spot analyses for analyses that are started during the grace period. Section 93.111(c) of the conform ity rule allows conformity determinations for projects based on the previous version of an emissions model to be completed after the end of the MOVES2010 grace period, if the analysis was begun before the end of the grace period. 12 Quantitative PM 10 and PM 2.5 hot-spot analyses can also be completed for conformity purposes during the grace period, if desired. Ho wever, any quantitative PM 10 and PM 2.5 hot-spot analyses conducted during th e grace period must use MOVES20 since MOBILE6.2 does not have the capabilitie s to conduct project-level PM emiss analyses and is therefore not approved for this purpose, as de scribed above. Any quantitative PM 10 or PM 2.5 hot-spot analysis for conformity purposes begun after the end of the grace period must use MOVES2010. EP A is currently working with DOT to 10,

ions

10 See EPA and FHWA’s joint “Transportation Conformity Guidance for Qualitative Hot-spot Analyses in

PM 2.5 and PM 10 Nonattainment and Maintenance Areas,” EPA420-B-06-902 (March 2006).

11 See EPA’s March 10, 2006 final conformity rule for further information (71 FR 12498-12502).

12 Since previous emissions models have not been approved in the past for quantitative PM hot-spot analyses, a qualitative PM analysis is considered the previous version of the relevant emissions model for the purposes of 40 CFR 93.111(c).

14prepare guidance on how to conduct quantitative PM 2.5 and PM 10 hot-spot modeling for transportation conformity purposes. 13 See Question 15 for what emissions model must be used when completing quantitative PM hot -spot analyses for certain projects with

California. in

14. What model should be used for the first transportation plan and TIP conform ity determinations for areas designa ted nonattainment for the 2006 PM 2.5 NAAQS?

Areas designated nonattainment under the 2006 PM 2.5 NAAQS have a one-year grace period before conformity applies (40 CFR 93.102(d)). When completing their initial conformity determinations for this NAAQS, areas outside Californi a will have the option to take advantage of any time that remain s in the two-year MOVES2010 grace period at that time. In general, initial transportati on plan and TIP conformity determinations for

the 2006 PM 2.5 NAAQS can be made using either MOBILE6.2 or MOVES2010, but this decision should be made on an area-by-area basis. See Questions 10, 11, and 12 for further details on using MOVES2010 fo r regional emissions analyses.

See EPA’s “Interim Transportati on Conformity Guidance for 2006 PM 2.5 NAAQS

Nonattainment Areas” ( EPA-420-B-09-036, November 2009 ) for more information. EPA will also publish a final conformity rule in the near future that will include final conformity requirements for the 2006 PM 2.5 NAAQS. 14 Areas should consult with their EPA Regional Office on implementing conformity for the 2006 PM 2.5 NAAQS.

15. What model should be used for quantitative PM 10 and PM 2.5 hot-spot analyses for certain project-level conformity determinations in California?

For quantitative PM 10 and PM 2.5 hot-spot analyses completed for projects within California, EMFAC2007 must be used in stead of MOVES2010. EPA previously approved the use of EMFAC2007 for SIP de velopment in California and for most transportation conformity analys es (i.e., all regional emissi ons analyses and CO hot-spot analyses) (73 FR 3464) and intends to extend this approval to quant itative PM hot-spot analyses in the same Federal Register notice that approves MOVES2010 for transportation conformity use. Directi ons for using EMFAC2007 for quantitative PM hot-spot analysis will be in cluded in EPA’s “Transportati on Conformity Guidance for Quantitative Hot-spot Analyses in PM 2.5 and PM 10 Nonattainment and Maintenance Areas” when that guidance is released.

13 See 40 CFR 93.123(b)(4). The requirements for quan titative PM hot-spot analyses will not take effect until EPA releases modeling guidance on this subject and announces in the Federal Register that these requirements are in effect.

14 See http://www.epa.gov/otaq/stater eso urces/transconf/policy.htm for the interim guidance and EPA’s future final conformity rule.

1516 U SING MOVES2010 FOR O THER P URPOSES

16. Can MOVES2010 be used to estimate greenhouse gas emissions?

MOVES2010 is currently the best tool EPA has for estimating greenhouse gas (GHG) emissions from the transportation sector . It is a significant improvement over MOBILE6.2 and previous versions of M OVES for GHG estimation. State and local agencies estimating GHG emissions in th e transportation pla nning process should consider using MOVES2010 for GHG em issions analyses in the future.

17. Can MOVES2010 be used to estimate mobile source air toxics?

MOVES2010 estimates emissions for the follo wing mobile source air toxics (MSATs): benzene, 1,3-butadiene, formaldehyde, acetalde hyde, acrolein, naphthalene, ethanol, and

MTBE. MOVES2010 is EPA’s best available tool for quantifying emissions of these MSATs. State and local agencies, academic in stitutions, and other in terested parties who are interested in analyzing MSAT emissions from transportation projects are encouraged to use MOVES2010. EPA is working to inte grate additional MSATs into the MOVES modeling framework in the near future.

EPA notes that there are no SIP and transporta tion conformity requirements for air toxics. Regarding the analysis of MSAT emissions in the National Environmental Policy Act (NEPA) process, DOT has responsibility for implementing NEPA for federally-funded or approved transportation projects.