Need for Handbook No federal requirement for state DOTs and MPOs to consider GHG impacts of transportation plans, but there is growing interest in analyzing GHG emissions in the transportation planning process. Some state DOTs and MPOs may have state or local requirements. State DOTs and MPOs still face questions: How can GHG emissions analyses be applied in the transportation planning process? What are the most appropriate methods to use? What data are needed, and what are common sources? What are the strengths and limitations of different approaches?
Handbook Purpose To help state DOTs and MPOs of all sizes and capabilities understand possible approaches, data sources, and step-by- step procedures for analyzing GHG emissions in the planning process. Designed to: Be user friendly and informative, particularly for State DOTs and MPOs that have limited experience with emissions analysis. Provide references to more detailed user manuals and technical resources.
Including GHG Analysis in the Transportation Planning Process
Types of GHG Analysis within the Planning Process GHG analysis falls into three broad categories based on purpose and timeframe: 1. Inventories - past or current emissions levels; 2. Forecasts - predictions about future emissions, potentially under different transportation investment or policy scenarios; 3. Strategy analysis – emissions effects of transportation strategies or sets of strategies, either to document the impact of existing programs or to forecast the potential impacts.
Handbook Sections Handbook includes: 1.Introduction 2.Overview: Estimating GHG Emissions in the Planning Process 3.What Methodologies are Applicable in Your Situation? 4.Fuel-based Methods 5.VMT-based Methods 6.Alternative GHG Estimation Approaches 7.Specific Transportation Strategy Analysis Methods 8.Additional Considerations in GHG Analysis: Lifecycle Analysis and GHG Emissions from Transportation Construction & Maintenance 9.References 8
BACKGROUND ON GREENHOUSE GASES IN TRANSPORTATION 9
Greenhouse Gases Gases that trap heat in the atmosphere are often called greenhouse gases (GHGs) The principal GHGs that enter the atmosphere because of human activities are: Carbon Dioxide (CO 2 ) Methane (CH 4 ) Nitrous Oxide (N 2 O) Fluorinated Gases
GHGs are Different GHG emissions differ from criteria air pollutants currently regulated under the Clean Air Act: The environmental impact of GHGs is the same regardless of where or when they are released. GHGs encompass at least six different gases. There are no means of using air quality monitoring data to designate nonattainment areas. GHGs persist in the atmosphere for decades; thus cumulative emissions are important. 11
Transportation GHGs About one third (27%) of GHG emissions in the U.S. come from transportation. U.S. GHG Emissions Allocated to Economic Sectors, 1990 - 2010 Most transportation emissions come from on-road sources.
Factors affecting GHG Emissions from Transportation CO 2 emissions are a function of vehicle technology and activity, transportation infrastructure, and external factors.
Why Include GHGs in the Planning Process? Better understand environmental implications of LRTPs Address environmental sustainability within performance- based planning efforts Support state/local climate action planning efforts
Why Include GHGs in the Planning Process? (continued) Complement planning and environment linkages (PEL) efforts PEL is designed to help planners address complex environmental challenges early on. Can help minimize duplication of effort later on in the National Environmental Policy Act (NEPA) process for projects included in the plan. A planning level analysis has several advantages compared to project-level analysis: System-wide approach Broader geographic scope Longer time scale 16
Methods for Estimating On-Road GHG Emissions Two common methods exist for estimating GHG emissions: Fuel-based methods Note: The emissions factor will depend on the fuel type VMT-based methods Note: The emissions factor will depend on vehicle type, technology/fuel type, speeds and operating conditions; different emissions factors are available for CO 2, N 2 O, and CH 4 Fuel Consumed Emission Factors CO 2 Emissions GHG Emissions VMT Emission Factors
Methods for Estimating On-Road GHG Emissions (continued) Other approaches discussed in the Handbook include: Alternative GHG Estimation Approaches Commodity flow based methods Energy and Emissions Reduction Policy Analysis Tool (EERPAT) Specific Transportation Strategy Analysis Methods Conducted to analyze specific strategies, such as land use, operations strategies, and freight strategies. Often used in combination with fuel-based or VMT-based methods. Additional Considerations in GHG Analysis Life cycle analysis Transportation construction and maintenance emissions
Fuel-based Methods: An Overview Fuel Consumed (e.g., gallons) Emission Factors (e.g., CO2 per gallon) CO2 Emissions 22 Only accounts for CO 2, not other GHGs Most applicable at the state level, where fuel data are typically available Assigns emissions based on fuel sales; may not match with transportation planning assumptions about VMT Forecasts typically do not account for impacts of transportation investments
Fuel-based Methods: Collecting Fuel Consumption Data Fuel Consumed (e.g., gallons) Emission Factors (e.g., CO2 per gallon) CO2 Emissions Common Data Sources: State fuel sales data and projections (generated for tax revenue purposes) FHWA’s Highway Statistics report Data from the Energy Information Administration (EIA), including forecasts in the Annual Energy Outlook
Fuel-based Methods: Calculating Emissions Fuel Consumed (e.g., gallons) Emission Factors (e.g., CO2 per gallon) CO2 Emissions 24 Emissions factors vary by type of fuel (e.g., motor gasoline, diesel, LPG) Common Sources / Tools: Emissions factor tables from EIA or the Environmental Protection Agency (EPA) Tools that include emissions factors : State Inventory Tool (SIT) State Inventory Projection Tool
Fuel-based Methods: Emissions Factors Transportation FuelEmission Factors Kilograms CO 2 Per Unit of Volume Kilograms CO 2 Per Million Btu Aviation Gasoline8.32per gallon69.19 Biodiesel -B1000per gallon0 -B208.12per gallon59.44 -B109.13per gallon66.35 -B59.64per gallon69.76 -B29.94per gallon71.80 Diesel Fuel10.15per gallon73.15 Ethanol/Ethanol Blends -E1000per gallon0 -E851.34per gallon14.79 -E10 (Gasohol)8.02per gallon66.30 -M1004.11per gallon63.62 -M854.83per gallon65.56 Motor Gasoline8.91per gallon71.26 Jet Fuel, Kerosene9.57per gallon70.88 Natural Gas54.60per thousand cubic feet53.06 Propane5.74per gallon63.07 Residual Fuel11.79per gallon78.80 Emissions Factors, available at: http://www.eia.gov/environment/data.cfmhttp://www.eia.gov/environment/data.cfm Source: U.S. Energy Information Administration
Example: Vermont Statewide GHG Inventory and Forecast Vermont GHG Inventory: Developed using SIT software and methods in Emissions Inventory Improvement Program (EIIP) guidance Default motor fuel consumption data within SIT were replaced with gasoline consumption estimates from state tax data Vermont GHG Projections: Estimated future fuel consumption using VMT projections combined with estimated vehicle fuel economy from EIA and information on new vehicle GHG standards 26 SIT CO 2 emissions factors were applied to calculate CO 2 emissions
VMT-based Methods: An Overview 28 VMT (miles) Emission Factors (grams / mile) GHG Emissions Can be used to estimate CO 2 and other GHGs Relies on VMT data commonly used in transportation planning Can be conducted at various levels of sophistication Involves two main components: 1) Developing VMT estimates; 2) Estimating emissions (relying on simple emission factors or use of sophisticated emissions models)
VMT-based Methods: Estimating VMT 29 VMT (miles) Emission Factors (grams / mile) GHG Emissions The first step in developing a GHG emissions estimate is developing estimates of VMT. There are a range of data sources and methods for estimating current and future VMT.
VMT-based Methods: Estimating VMT using Vehicle, Household, and Land Use Data Simple Approaches Vehicle Odometer data Data on miles traveled per vehicle from inspection programs or registration data. Household Travel Survey data Surveys can be used to estimate VMT by trip purpose or household characteristics and apply to a region or state Land Use data Use land use based trip generation factors to estimate vehicle trips, and then multiply by average trip lengths to calculate VMT Often applied at a small geographic scale (e.g., county or city or sub-area) and used for forecasts 30
VMT-based Methods: Estimating VMT using HPMS Data or Network-based Travel Model 31 Traffic count and Travel Model data HPMS Data on traffic volumes submitted by all State DOTs to FHWA; can be used to estimate VMT by functional class. Can apply simple factors or more sophisticated approaches to estimate future VMT. Travel model data Readily available in most MPOs, commonly used for forecasting future conditions. Accounts for factors such as land use patterns and transportation investments in developing forecasts
VMT-based Methods: Estimating Emissions Emissions rates depend on vehicle type, technology/fuel type, speeds, and operating conditions 32 VMT (miles) Emission Factors (grams / mile) GHG Emissions There are multiple ways to apply emissions factors Simple factor Look-up table only accounting for fleet characteristics Look-up table accounting for fleet characteristics and speeds MOVES inventory mode MOVES emission rates
VMT-based Methods: Estimating Emissions (continued) 33 For resources on using MOVES, see: http://www.epa.gov/otaq/stateresources/ghgtravel.htm http://www.epa.gov/otaq/stateresources/ghgtravel.htm Guidance: Using MOVES for Estimating State and Local Inventories of On-Road Greenhouse Gas Emissions and Energy Consumption: http://www.epa.gov/otaq/stateresources/ghgtravel.htm E PA’S MOVES (Motor Vehicle Emission Simulator) EPA’s MOVES model is the most robust methodology. The model works by simulating actual vehicle drive cycles, including the effect of travel at different speeds and vehicle power loads.
VMT-Based Methods: Example DVRPC Regional Inventory (Philadelphia) DVRPC developed a regional GHG emissions inventory HPMS data used to determine VMT total Through traffic was estimated based on travel demand model, and subtracted from total VMT apportioned to municipalities based on trip origins, destinations & length Emissions are mapped per acre, and per population and employment 34
VMT-Based Methods: Example Atlanta Regional Commission GHG Forecasting Atlanta Regional Commission (ARC) modeled emissions impact of various land use scenarios describing different types of growth. Used 4-step travel demand model and emissions model. Allowed ARC to demonstrate impact of various strategies.
Alternative GHG Estimation Approaches Methods to address specific needs: Commodity Flow Methods – for freight-related emissions Travel models are generally geared toward passenger traffic Commodity flow methods may be used to estimate freight emissions (see NCFRP Report 4*) Energy and Emissions Reduction Policy Analysis Tool (EERPAT) - for policy analysis Many forecasting methods do not account for full range of GHG reduction strategies, including policies on pricing, incentives for energy efficient vehicles, and land use EERPAT conducts a screening-level analysis of a range of strategies See http://www.planning.dot.gov/FHWA_tool/ for more informationhttp://www.planning.dot.gov/FHWA_tool/ 37 * http://onlinepubs.trb.org/onlinepubs/ncfrp/ncfrp_rpt_004.pdf,
Specific Strategy Analysis Methods Most travel forecasts cannot evaluate certain GHG reduction strategies. Handbook addresses specific analyses for: Transportation Demand Management (TDM) strategies (e.g., employer-based programs, parking pricing) Land use strategies (e.g., land use mixing, pedestrian friendliness) Transportation system management and eco-driving strategies (e.g., traffic surveillance, ramp metering, emergency management, eco- driving) Freight strategies (e.g., idle reduction programs, logistics improvements) Examples for each are included in the Handbook 38
Additional Considerations in GHG Analysis Transportation emissions come from sources other than motor vehicles. Lifecycle analysis methods account for direct emissions from motor vehicles and emissions associated with connected activities (e.g., vehicle disposal, fuel processing, electricity used in transit) Transportation infrastructure construction and maintenance activities also produce emissions, which can be analyzed 39
Key Points GHG emissions can be an important planning consideration. To get started, determine: What is the goal of the analysis? What data, tools, and resources do we have available? What variables do we want to analyze? Approaches can vary from simple to complex Recognize the strengths and limitations of different approaches – what may be applicable in one case may not be in another Use of VMT data/forecasts with EPA’s MOVES model provides the most robust methodology for most planning applications More detailed resources, documentation, and modeling guidance are available 41
Contact Information Jody McCullough Federal Highway Administration Office of Planning 1200 New Jersey Avenue SE Washington, DC 20590 Jody.McCullough@dot.gov 202-366-5001