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Onroad Workgroup

Collaborative Wiki Main Page

Inventory Collaborative Google Drive Link


Co-leads: Julie McDill (MARAMA), Alison Eyth (EPA)

Molly Birnbaum - Alaska, Brian Sullins - Alabama, Sylvia Vanderspek and Leo Ramirez - California, Rebecca Simpson - Colorado, Dale Wells - Colorado, Alexandra Catena - D.C., Gil Grodzinsky - Georgia, Marc Bennett - Massachusetts, Marcia Ways - Maryland, Todd Pasley - North Carolina, John Gorgol - New Jersey, Rob McDonough and Chris Rochester - New York, Mike Maleski - Ohio, Chris Trostle - Pennsylvania, Susanne Cotty - Pima County, Carla Bedenbaugh - South Carolina, Chris Kite - Texas, Peter Verschoor and Rick McKeague - Utah, Sonya Lewis-Cheatham - Virginia, Chris Bovee and Mike Friedlander - Wisconsin, Michelle Oakes - Tennessee, Brian Timin - EPA OAQPS, Daniel Bizer-Cox - EPA OTAQ, Dave Brzezinski - EPA OTAQ

Onroad Workgroup Meetings

MOVES MJO meetings held the third Thursday of the month at 2:00 p.m. Eastern. Additional 2016-specific meetings may be scheduled as needed.

April 19, 2018


  • Updated Evaluation of MOVES2014 with Real World Measurements (Darrell Sonntag, USEPA)
  • Overview of CRC Real World Emissions Workshop - March 2018 (Julie McDill)
  • Submitting 2016 activity data for beta version (Alison Eyth)
  • Action items from last call


1. Updated Evaluation of MOVES2014 with Real World Measurements – Darrell Sonntag (USEPA)

Motivation: Modeled NOx was higher in summer months than observed monitored data.

MOVES Project-scale – MOVES emission rates compare well to University of Denver RSD data when using the location-specific MOVES inputs MOVES national scale – Using the MOVES default inputs show clear over-prediction. Two key inputs contribute the most difference between project-level and county/national inventory estimates

  • Vehicle age: younger fleets at measurement sites than in national default county-level inputs
  • Vehicle operation: vehicle operation (speeds/acceleration) milder at measurement sites than in the national default county-level inputs

An analysis of 3 studies (2 PEMS, 1 Roadside) suggests high power light-duty NOx rates are worth further evaluation – NOx-VSP trends in MOVES are steeper at high power than measured for:

  • Tier 1 passenger cars and trucks
  • Tier 2 passenger trucks
  • MOVES estimates Tier 2 trucks have higher emissions than Tier 2 cars. This is not observed in the PEMS and RSD data They are looking into why this happened, since it should not be.

2. CRC Real World Emissions Workshop - March 2018 – An overview – Julie McDill (MARAMA)

On March 19-21 Julie McDill attended the Coordinating Research Council Meeting on Real Life Mobile Emissions held in Anaheim, CA. Real life mobile emissions can now be measured using portable systems (PEMS) that are small and light enough to be carried inside a motor vehicle during a driving test, rather than on the stationary rollers of a dynamometer that only simulates real-world driving. Results from PEMS show that actual emission factors and overall mobile emissions may be significantly different than estimated using dynamometer simulations and used in the MOVES Model. PEMS offer a more realistic view of emissions which are more variable than was prior understood. Real World emissions are influenced by Vehicle technologies, Driving styles and External environment. Light Duty (LD) NOX Emissions from 2008 to 2016 are down 55%, however black carbon emissions are unchanged. Light Duty (LD) emissions are now dominated by emissions during cold starts. All other LD processes, including running emission, don’t contribute much to total NOX emissions.

Actual Heavy Duty (HD) NOX emissions exceed the certification standard of 0.2 g/bhp and range between 0.2 -> 3.25 g/bhp. Part, but not all, of this excess is due to the use of banked credits. Heavy Duty (HD) emissions vary by model year with first generation (2013) HD NOX emission higher than later Model years (2016). DPF may be less efficient at oxidizing NOX due to better tuning of control systems. Heavy Duty emissions are affected by speed with Particle Number (PN) increasing and NOX decreasing at high speeds. HD NOX emissions are generally higher when idling (0.3 g/bhp) Use of Ethanol & biofuel increased dramatically after 2005 renewable fuel std. However, it is still less than ½ of biofuel target for 2022. Ethanol enriched fuel raises the fuel octane. As a result aromatics are no longer needed to achieve adequate octane levels to enhance performance. This shift resulted in 5% Ozone reduction but increased ambient concentration of ultrafine particle. Uncertain of how PM2.5 is affected. – Change in emissions resulting from ethanol added to fuel:

  • Higher SOA - Ethanol increases SOA formation in situations when non-oxidation reactions occur – some (like E20) create a lot of SOA.
  • Lower CO & Benzene
  • Higher aldehydes – examples: Formaldehyde & Acetaldehyde Carbonyls Carbon with double bond to oxygen and 2 other attachments Aldehydes have a High MIR - Reactive precursor for ozone. Motor vehicles major sources.
  • Lower toxicity because lower BTEX
  • Photochemical models lack parameters to predict the effect of biofuels on ambient PM2.5 mass concentration.

3. Submitting activity data - deadline and methods – Alison Eyth (USEPA)

  • Original date for 2016 Activity data was April 15, but this has been relaxed to May 15 – Voluntary to submit
  • Activity data can be provided in SMOKE FF10 format or by county and HPMSvtype in spreadsheets
  • Data can be emailed to
  • Activity data for states that do not provide data will be projected to 2016 using a default approach All 2014 NEI v2 Onroad and Nonroad supporting data are available. See presentation for links to download information / data files. Output for each sector should be available by end of April. FY18 budget not yet determined for Platform 2016
  • a summary of VMT by HPMSVtype for each county is available, and a comparison to what S/Ls have provided so far

4. . Action items from the last call: a.       Providing the hoteling Shapefile currently in use: Same file in spreadsheet format is uploaded to dropbox and sharefile b.       Provide SCC descriptions for activity data:

February 15, 2018


  • Development of 2016 onroad alpha emissions (Alison Eyth)
  • Review of which states and locals plan to submit 2016 inputs (Julie McDill)
  • CRC project for 2016 VIN-decoding (Mark Janssen)


1. 2016 Alpha Onroad Emissions Presentation

  • 2016 VMT was projected from 2014v2 VMT using state-urban, state-rural factors except where those factors proved unreasonable
  • 2014v2 ratios of VMT to hoteling and VMT to VPOP were preserved in 2016.
  • Pollutant reductions from 2014 to 2016: CO -15%, NH3 -6%, NOX -16%, PM10 -9%, PM2.5 -19%, SO2 -3%, VOC – 16%

2. Summary of state submission plans for 2016 onroad data

3. Developing age distributions for 2016

  • VIN Decode for Age distribution: More time required to negotiate with IHS and ERG on the 2016 VIN decode. Prices up since the 2011 work(30%) and CRC funds are limited. Plan to decode the Light Duty Vehicles as we did in 2011 and EPA did in 2014. We will not be able to get a national age distribution for Heavy Duty Vehicles. Work with OAQPS to get county groups updated. Project complete in late summer/September.
  • State/IHS comparison: Inadequate resources to compare state and IHS methodologies to collect and interpret VINs with the A-115 project. OTAQ had a proprietary copy of the age distributions that drove the 2014 work. It does not have individual VINS but does have vehicle counts by make, model, and year with the assumed MOVES classification. Mark working folks who signed up for the comparison group to look at the differences in methodology and hopefully have report by June 1st to inform 2016 work.

4. Glider trucks - an impromptu conversation was held

5. Next call: March 15 at 2 Eastern / 1PM CEN / Noon MTN / 11AM PAC

January 18, 2018


  • Overview of 2016 Collaborative Onroad Workgroup - Alison Eyth (OAQPS)
  • Options for developing 2016 alpha version activity data – Alison Eyth (OAQPS)


Presentation is available here: Options for developing 2016 activity data

1.       Initiation of the 2016 collaborative onroad workgroup - Alison Eyth – (Presentation available) Alison presented on options to create an alpha 2016 onroad inventory by adjusting 2014v2 MOVES inputs using FHWA data for 2016 which was recently released. After the options were presented, the workgroup was polled. The percent of states on the call that preferred each of the 4 options described by Alison are as follows:

  • Option 1 - State+road type (33 %)
  • Option 2 - State+urban, State+rural (40 %)
  • Option 3 - State overall (19%)
  • Option 4 - State+restricted, State+unrestricted (5%)

By a narrow margin, the workgroup prefers option 2.

2.       Please complete a questionaire concerning state plans to submit state specific 2016 data. Please visit the link below by COB Feb 1 to indicate what data you will submit (2016 VMT, VPOP, Hoteling hours, changes to representative counties, activity data for 2023 and 2028)

Please note:

  • 2016 datasets must be provided by April 15, 2018.
  • 2023/2028 activity data by June 2018

3.       Rate mode MOVES Emission Factors The latest MOVES EF lookup tables are uploaded to UNC google drive for you to share. Please let me know if you have any question. - From: Baek, Bok Haeng []

4.       Mark Janssen (LADCO) recruited a number of states to work with CRC on the 2016 VIN decode to be used for ozone SIP planning. As part of this round they are comparing the IHS methodology used for the 2011/2014 NEI with state efforts to create age distributions from decoded VINs. Our goal is to do a county by county comparison of MOVES vehicle type population determinations between the IHS and the states and explore the reasons why they would differ. Good response so far from several states. No target as yet of when the results will be available, but will coordinate with Alison on folding results into Beta 2016 inventory.

5.       Next Call: Thurs Feb 15 @ 2PM Eastern / 1PM Cen / Noon Mtn / 11AM PAC

Workgroup Kickoff Email from Alison Eyth 1/12/2018

As the co-chairs of the 2016 collaborative onroad workgroup, Julie McDill and I would like to welcome you to the workgroup and to thank you for your willingness to participate! For your reference, the workgroup members are listed at the end of this email. We have participation throughout the country, which is great. We look forward to a productive calendar year of 2018.

Our first meeting of 2018 will be held coincident with the existing MOVES MJO workgroup, which is larger than the 2016 workgroup. Some 2016-specific meetings may be scheduled later in the year. The MOVES MJO workgroup meetings are the third Thursday of each month at 2:00 eastern, so one is scheduled for next Thursday 1/18. If you have not registered for the MOVES MJO workgroup webinars, please register here:

Our first goal for the 2016 onroad workgroup is to provide you with the 2016 alpha platform onroad emissions, as those would be a starting point for the 2016 platform, although they will be improved upon in the beta and v1 versions of the platform which will include more state-submitted data. EPA will create the 2016 alpha emissions for the community’s use and review. To create the emissions, we need both emission factors and activity data to pair with them. EPA has developed a set of 2016 emission factors that are compatible with those used to develop 2014NEIv2. To create these, fuel properties and the year of the run were updated to 2016, as were affected model years for I/M programs. For those familiar with the age distribution projections used in recent platforms, no age distribution projections were applied while creating these emission factors and instead the 2014 v2 age distributions were used as-is.

The main remaining issue to be resolved prior to creating the emissions is what activity data to use. EPA typically uses VMT and other data from FHWA for historic years. For the 2014NEI, FHWA provided county-specific VMT data by road type and this was used as the basis for creating an “EPA default” activity data set that was used for states that did not submit and for some submitting states for specific vehicle types found to have quality assurance issues. FHWA has recently provided 2016 county-specific VMT data for most road types at the same level of detail as was provided for 2014, although EPA had to fill in some data for local roads based on state total data allocated to counties based on population and data in the VM-2 table shown here: Note that FHWA is working to populate the full set of 2016 highway statistics but they are not all completed/posted yet – many attributes besides VMT will become available at this link:

Once we finished creating a county-specific dataset of VMT factors for the MOVES road types 2, 3, 4, and 5, we found a broader spread in the factors than was anticipated. We had been expecting most changes in activity from 2014 to 2016 to be within +/- 10%, but we found that some were much larger. We computed ratios specific to road type, a broader grouping of urban and rural road types, and a yet broader grouping of county overall changes. We found that some of the county total factors were as low as 0.47 and as high as 2.7. The larger changes seem to be prevalent in certain states – particularly Georgia, Texas, and Wisconsin. We are thinking that perhaps some underlying method for computing the VMT was changed for those states in the intervening years, thereby making these county-level ratios incompatible with the 2014 data (see the attached 2016v2 onroad VMT projection factors.xlsx for details). It is my understanding that the FHWA VMT data actually originates with the states and is collected and collated by DOT through a process similar to how the NEI collects and collates emissions data from states. If you are a representative of one of the states with broadly changing factors and are able to find out if some change was made in your state’s reporting of VMT, that would be useful information for the workgroup to have.

In the meantime, we are looking for an alternative that would allow us to apply some factors to the 2014 activity data (which includes many state submissions and a lot of work to put it exactly into the level of detail used by MOVES) so that those data could better represent year 2016. As a possible alternative to county-specific factors, we have developed state road type-level factors that could be used to create the alpha version VMT (and VPOP, which would be derived from by retaining the VMT/VPOP ratios from 2014). These factors are shown in the attached state-road 2014-16 growth factors from VM-2.xlsx. We could apply the factors specific to road type, or the factors specific to rural roads, urban roads, or overall for the state. The overall state factors will result in the smallest changes from the 2014 VMT to the alpha version. We are interested to receive your thoughts on this. I will prepare a presentation for next Thursday’s webinar, but webinars are not always the easiest forum for discussion. So, if you have any suggestions regarding the factors to use, or another idea prior to next week’s meeting , please email Alison and Julie, and we will collate the responses prior to next week’s meeting. Note that I have sent this email using Bcc for the members to prevent long threads going to everyone’s Inboxes, but we can discuss the preferred communication methods at next week’s meeting.

Also, I soon should be able to provide the 2014NEIv2 onroad emissions and draft documentation for how they were developed – perhaps by next week’s meeting. The overall 2014NEIv2 release for all sectors was delayed due to a technical glitch, but we do plan to finalize it this month.

December 20, 2017


  • Overview of the Dec 6 MOVES FACA – Dale Wells (CO)
  • Updates to 2014NEIv2 Onroad Mobile Emissions – Alison Eyth (OAQPS)

Development of 2014NEIv2 Onroad Mobile Source Emissions