Impacts of New Mobile Source Regulations on Emission Reductions from VMT-Based Transportation Control Strategies: Key

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1 0 0 0 Impacts of New Mobile Source Regulations on Emission Reductions from VMT-Based Transportation Control Strategies: Key Considerations for Planning Agencies Alexandra Marcucci, Corresponding Author Sierra Research Inc. a Trinity Consultants Company 0 J Street, Sacramento CA Tel: -- Fax: --; amarcucci@sierraresearch.com Sung Hoon Yoon Sierra Research Inc. a Trinity Consultants Company 0 J Street, Sacramento CA Tel: -- Fax: --; syoon@ sierraresearch.com Thomas R. Carlson Sierra Research Inc. a Trinity Consultants Company 0 J Street, Sacramento CA Tel: -- Fax: --; tcarlson@sierraresearch.com James M. Lyons Sierra Research Inc. a Trinity Consultants Company 0 J Street, Sacramento CA Tel: -- Fax: --; jlyons@sierraresearch.com Word count:,00 text + ( tables x 0 words (each)) + figures x 0 words (each)) =,00 Submission Date: November, 0

2 Marcucci, Yoon, Carlson, Lyons 0 0 ABSTRACT This study examined the impacts of increasingly stringent mobile source regulations on the ability of regional planning agencies to comply with federal and state air quality and climate goals. Planning inventory emission factors were derived using two versions of Californiaspecific emissions models EMFAC0 and EMFAC0 for the South Coast and San Joaquin Valley nonattainment areas. Using emission factors from California s emission inventory models that reflect recently enacted mobile source regulations, differences in emission benefits of adopted regional plans were assessed using planning scenario travel data developed in support of climate change targets established by California Senate Bill. The results show that as the on-road fleet becomes cleaner over time, regional planning agencies will be challenged to achieve the reductions in criteria and climate change pollutants anticipated from transportation control measures and other strategies focused on reducing vehicle miles travelled. In the case of criteria pollutants, per-mile emission factors were reduced by as much as 0 percent for oxides of nitrogen, 0 percent for reactive organic gases, 0 percent for fine particulate, and percent for carbon dioxide emissions by 0 due to implementation of more stringent federal and state mobile source regulations for light- and heavy-duty sectors. Although emission inventory reductions are typically welcomed by policymakers, VMT-based control strategies will become less effective over time, requiring regional planning agencies to consider more aggressive programs, a shift to technology-based strategies and traffic-flow improvement projects, and increased cost-effectiveness limits in order to obtain federal funding for these measures. Keywords: GHG reduction strategies, Senate Bill (SB), transportation control measures, mileage (VMT) reductions, vehicle emissions modeling, EMFAC.

3 Marcucci, Lyons, Carlson, Yoon INTRODUCTION Over the past decade, the State of California has enacted a variety of regulations developed to reduce emissions of criteria and climate change pollutants from the mobile source sector. In general, these regulations reduce mass emissions per mile traveled (i.e., grams per mile [g/mile]). In May 0, the California Air Resources Board (CARB) released the agency s Mobile Source Strategy (MSS) () that outlines the State s plans for enacting additional regulations over the next years targeting further emissions reductions from the mobile source sector in order to achieve the State s air quality and climate goals. The MSS focuses on the South Coast Air Basin and reports that the proposed state and federal mobile source programs will achieve an additional 0 percent reduction in smog-forming pollutants reactive organic gases (ROG) and oxides of nitrogen (NOx) by 0. In addition, the MSS is estimated by CARB to reduce statewide greenhouse gas (GHG) emissions by an additional 0 percent in support of Governor Jerry Brown s Executive Order B-0- and the goals of Assembly Bill (AB ), the California Global Warming Solutions Act of 00. The main components in the menu of proposed regulations are intended to dramatically expand the deployment of zero- and near-zero-emissions technologies and establish more stringent emission standards for criteria and climate change pollutants for light- and heavy-duty vehicles. These regulations are also likely to be enacted in states that have adopted the California vehicle program pursuant to Section of the Clean Air Act and, in most cases, EPA is expected to adopt analogous regulations to complement the actions taken by California. Against the backdrop of the diminishing gram per mile emission levels, regional planning agencies (RPAs) are tasked with achieving regional air quality and transportation conformity goals, and California RPAs are also tasked with meeting per-capita GHG emission reductions required by Senate Bill (SB ). The Transportation Conformity Rule () requires RPAs in nonattainment areas to timely implement transportation control measures (TCMs) contained in a State Implementation Plan (SIP) for the region. If funds programmed for TCMs do not become available or if the schedule identified in a SIP cannot be met, the RPA faces serious consequences, one of which could be a nonconforming regional transportation plan. Further, the Transportation Conformity Rule specifically defines TCMs as measures that reduce vehicle use, and consequently vehicle miles travelled (VMT), or improve traffic flow. Clean Air Act Section 0(f)()(A) () lists categories of TCMs, of which directly focus on reducing travel. In addition, many RPAs in the nation have adopted transportation demand management (TDM) programs as part of their long-range planning process. These TDMs, and similar programs, aim to reduce regional travel through strategies that increase access to transit, provide active transportation options, and encourage ridesharing. Historically, TDM strategies have widely documented benefits that result from reducing or shortening single-occupancy vehicle (SOV) trips, which in turn reduce regional VMT, improve congestion, and reduce criteria pollutant and GHG emissions (). TCMs and TDMs also receive priority for federal Congestion Mitigation and Air Quality (CMAQ) funding if the projects meet certain cost-effectiveness limits, which are established in terms of dollars spent per ton of pollutant emissions avoided. In California, SB requires that RPAs make further investments in programs that curb VMT growth in order to reduce GHG emissions from light-duty vehicle travel. All of the aforementioned VMT-based strategies generally become part of the transportation planning process, and therefore the conformity demonstration process. What policymakers often fail to recognize is that while federal and state mobile source regulatory programs reduce emissions, they also make it increasingly more difficult for RPAs to

4 Marcucci, Lyons, Carlson, Yoon achieve reductions in mass-based emissions of criteria and climate pollutants through TCMs focused on VMT reductions, as well as to receive federal funding for transportation projects that rely on achieving cost-effective reductions in emissions. This study examines these issues in the context of two California regional planning areas and demonstrates the reduction in the TCM effectiveness over time. Although the analysis is limited to California, the findings clearly have relevance for many urban areas around the country. EVALUATION METHODOLOGY Emission Factor Modeling On December 0, 0, CARB released EMFAC0, which is the latest update to the EMFAC model and supersedes the previous version of the model, EMFAC0. While EMFAC0 includes changes to the VMT forecasting methodology and updates to select emission factors based on new vehicle test data, the biggest difference between the two models pertains to the assumptions related to new mobile source regulations enacted after the last release of EMFAC0. These regulations include CARB s Advanced Clean Cars Program, revisions to the agency s In-Use Truck and Bus Regulation and Tractor Trailer GHG Regulation, as well as the Phase Heavy-Duty Vehicle GHG Standards (). EMFAC0 will be required for conformity analysis on or after December, 0. During the model transition period (known as the grace period ), EPA allows California RPAs to use either EMFAC0 or EMFAC0 for regional conformity purposes (). This analysis begins with a comparison of the gram-per-mile emission factors generated by EMFAC0 and EMFAC0 for NOx, ROG, fine particulate matter (PM.), and carbon dioxide (CO) for the on-road vehicle fleets operating in the South Coast and San Joaquin Air Basins for analysis years 00 and 0 (Tables and Table ). To assess the direct impacts of new regulations accounted for in the EMFAC0 model update, default regional VMT and vehicle class distribution were extracted from EMFAC0 and used as inputs to EMFAC0. With these variables held constant between the two models, the observed emission factor differences could be directly attributed to new mobile source regulations enacted in California and their projected impacts on the future on-road fleet. We note that although only EMFAC0 has the ability to account for hourly speed distributions, the impacts of variations in VMT by speed between the two models are not expected to be significant and were not evaluated in this study. TABLE South Coast Emission Factor Comparison: EMFAC0 vs EMFAC Pollutant EMFAC 0 EMFAC 0 EMFAC 0 EMFAC 0 NOx, g/mile ROG, g/mile PM., g/mile CO, g/mile 0 0

5 Marcucci, Lyons, Carlson, Yoon 0 0 TABLE San Joaquin Valley Emission Factor Comparison: EMFAC0 vs EMFAC Pollutant EMFAC 0 EMFAC 0 EMFAC 0 EMFAC 0 NOx, g/mile ROG, g/mile PM., g/mile CO, g/mile 0 Regional VMT Reduction Evaluation and Emission Inventory Assessment This study used the actual travel data developed by two California RPAs in support of their Regional Transportation Plan (RTP) updates: () the 0 RTP prepared by the South Coast Association of Governments (SCAG) () and () 0 RTPs for the eight San Joaquin Valley (SJV) planning agencies (Fresno, Kern, Kings, Madera, Merced, San Joaquin, Stanislaus and Tulare Counties) (-). As noted above, California RPAs are required to comply with the requirements of SB, which include the development of a Sustainable Community Strategy (SCS) as part of the long-range transportation planning process. To support the evaluation of each SCS, CARB requires RPAs to model and compare various planning scenarios, which must include a business as usual or base case scenario and the actual planning scenario that the RPA plans to adopt. The difference in VMT modeled for the two scenarios is the anticipated VMT reduction that would be achieved with each corresponding RTP. Tables and show, for the South Coast and SJV, respectively, the RPA-modeled total regional VMT for the base case, the adopted planning scenario, and the corresponding VMT reduction that would be achieved with the RTP. The EMFAC0 and EMFAC0 emission factors for NOx, ROG, PM., and CO were then applied to the miles reduced with the Plan for each region to assess the differences in planning emission benefits for criteria and climate change pollutants in tons per day. TABLE South Coast 0 RTP/SCS VMT Reduction VMT, x000 miles Year Base Plan VMT Reduction 00,,, 0,,,00 TABLE San Joaquin Valley RPAs 0 RTP/SCS VMT Reduction VMT, x000 miles Year Base Plan VMT Reduction 00,0, 0 0,0 0,0,0

6 Marcucci, Lyons, Carlson, Yoon 0 0 RESULTS As shown in Tables and for the South Coast and San Joaquin Valley, respectively, there are differences in the 00 emission factors developed with EMFAC0 and EMFAC0, which indicate the significance of changes in methodology. As also shown, the decrease in emission factors becomes more apparent by 0. The differences increase in future years, largely because only EMFAC0 accounts for California s recently enacted mobile source regulations and because the impacts of total regional VMT and vehicle class distribution updates were held constant in this analysis. The significance of the difference in emission factors is reflected in the emission benefits expected to be achieved by each region s RTP. This is shown in Tables and, which compare the estimated emission reductions, in tons per day, for select criteria and climate change pollutants, as well as graphically in Figures through. As illustrated in Figures through, the reductions in tons per day emissions attributable to the RTPs in both regions are significantly lower with EMFAC0 in 0 when the impacts of the recently adopted measures are realized. Given CARB s regulatory schedule for recently enacted vehicle regulations and the delay in vehicle turn-over, fleet-average emission benefits are not as pronounced in 00 as in 0. For the SJV, NOx and ROG emission factors are actually slightly higher with EMFAC0, likely due to minor updates to vehicle age distributions and hydrocarbon speciation methodology for the new model. TABLE Comparison of RTP Emission Benefits in the South Coast Air Basin 00 0 Estimated Emission Benefits (tons per day) Reduction in Emission Benefits Estimated Emission Benefits (tons per day) Reduction in Emission Benefits (%) EMFAC EMFAC EMFAC EMFAC Pollutant NOx..0.%.0..% ROG.0..%...% PM %..0.% CO 0,,.%,,.% TABLE Comparison of RTP Emission Benefits in the San Joaquin Valley Air Basin 00 0 Pollutant EMFAC 0 EMFAC 0 Reduction in Emission Benefits EMFAC 0 EMFAC 0 Reduction in Emission Benefits (%) NOx, tons/day %. 0..% ROG, tons/day % % PM., tons/day % % CO, tons/day 0.% 0.%

7 Marcucci, Lyons, Carlson, Yoon FIGURE San Joaquin Valley RPAs 0 RTP/SCS Emission Benefits Comparison, 00 FIGURE San Joaquin Valley RPAs 0 RTP/SCS Emission Benefits Comparison, 0

8 Marcucci, Lyons, Carlson, Yoon FIGURE South Coast 0 RTP/SCS Emission Benefits Comparison, 00 0 FIGURE South Coast 0 RTP/SCS Emission Benefits Comparison, 0 By 0, emission benefits for the South Coast RTP are estimated to be reduced by % for NOx, % for ROG, % for PM., and % for CO emissions, while the VMT reduction achieved with the RTP does not change. For the SJV, use of EMFAC0 to model the emission reductions achieved by the RTPs adopted by the eight Valley RPAs results in comparable

9 Marcucci, Lyons, Carlson, Yoon differences: emissions benefits are estimated to be reduced by % for NOx, % for ROG, % for PM., and 0% for CO. This analysis shows that as new mobile source regulations are implemented, the emission benefits (in tons per day) from VMT-based control strategies are greatly reduced. Furthermore, this trend is expected to continue into the future, particularly with the state s strong focus on electrifying the transportation sector, making TCMs obsolete once vehicle emission factors reach zero or near-zero levels. In terms of climate change impacts, TCMs and projects that reduce VMT growth become less likely to achieve the CO emissions reductions needed to reach SB targets over time. For instance, SCAG s 0 RTP/SCS reports a % GHG per capita reduction from 00 levels by 0 based on EMFAC0 modeling. However, when the same VMT is modeled with EMFAC0, the resulting GHG emissions drop by over a third, resulting in only % GHG per capita reduction for the region, which would fail the CARB-set target of % and require the development of an Alternative Planning Strategy. CONCLUSION The results presented here clearly show that changes to new mobile sources regulations over time will substantially diminish the level of mass reductions in criteria and climate change pollutants that can be achieved through TCMs and other VMT reduction strategies. Although this analysis was performed only for California areas, similar results would be expected using any future MOVES model updates to evaluate other areas of the country, in light of federal actions on new mobile source regulations that are likely to mimic California efforts. As on-road emission factors continue to decrease, RPAs will have to enhance their planning process either to invest more funds into traditional TCMs in order to achieve more robust VMT reductions or to adopt other innovative strategies that complement federal and state fuel and technology-based programs. In addition, FHWA, state transportation departments, state and local air pollution control agencies, and transportation planning agencies should consider revising their current project cost-effectiveness estimates and thresholds to incorporate the impacts of new mobile source regulations on reductions achievable from VMT-based strategies in order to effectively administer CMAQ and other emissions-based funding programs. Specific to California, RPAs will be further challenged to meet their GHG per-capita targets required by SB, as regional VMT reduction will not yield the same amount of emission benefits as previously expected and modeled. To allow RPAs to continue to meet their climate change goals, CARB may need to further revise the SCS evaluation methodology to promote strategies that are not so focused on VMT reductions. Finally, the Clean Air Act definition of what constitutes a TCM may need to be reconsidered in order to make meaningful and emission-generating SIP commitments in the future.

10 Marcucci, Lyons, Carlson, Yoon REFERENCES. Mobile Source Strategy. California Air Resources Board. May 0. Determining Conformity of Federal Actions to State or Federal Implementation Plans. 0 CFR.. Clean Air Act 0(f)()(A), U.S.C. 0(f)()(A) (0). Cambridge Systematics., Inc. with Eastern Research Group, Evaluate the Interactions between Transportation-Related Particulate Matter, Ozone, Air Toxics, Climate Change, and Other Air-Pollutant Control Strategies, prepared at the request of the American Association of State Highway and Transportation Officials, National Cooperative Highway Research Project - (Task ), Transportation Research Board. July 00.. EMFAC0. California Air Resources Board Workshop Presentation, Sacramento, CA, November, 0. Official Release of EMFAC0 Motor Vehicle Emission Factor Model for Use in the State of California. U.S. Environmental Protection Agency. 0 FR. December, 0.. Technical Evaluation of the Greenhouse Gas Emissions Reduction Quantification for the Southern California Association Of Governments SB Sustainable Communities Strategy. California Air Resources Board. June 0.. Technical Evaluation of the Greenhouse Gas Emissions Reduction Quantification for the Fresno Council of Governments SB Sustainable Communities Strategy. California Air Resources Board. February 0.. Technical Evaluation of the Greenhouse Gas Emissions Reduction Quantification for the Kern Council of Governments SB Sustainable Communities Strategy. California Air Resources Board. July Technical Evaluation of the Greenhouse Gas Emissions Reduction Quantification for the Kings County Association Of Governments SB Sustainable Communities Strategy. California Air Resources Board. October 0.. Final 0 Regional Transportation Plan and Sustainable Communities Strategy (RTP & SCS). Madera County Transportation Commission. July, 0.. Regional Transportation Plan 0-00 Sustainable Communities Strategy for Merced County. Merced County Association of Governments. Adopted September, 00, Amendment adopted May, 0.. Technical Evaluation of the Greenhouse Gas Emissions Reduction Quantification for the San Joaquin Council of Governments SB Sustainable Communities Strategy. California Air Resources Board. May 0.. Technical Evaluation of the Greenhouse Gas Emissions Reduction Quantification for the Stanislaus Council of Governments SB Sustainable Communities Strategy. California Air Resources Board. June 0.. Reduction Quantification for the Tulare County Association Of Governments SB Sustainable Communities Strategy. California Air Resources Board. October 0.