handbook for estimating transportation greenhouse gases for integration into the planning process...
TRANSCRIPT
Handbook for Estimating Transportation Greenhouse Gases for Integration into the Planning Process
Jody McCulloughFederal Highway Administration
Webinar Agenda
1. Handbook Overview2. Background on GHGs in Transportation3. GHG Analysis in the Transportation Planning Process4. Methods and Tools for GHG analysis
Key Methods Fuel-based Methods VMT-based Methods
Alternative Approaches, Strategy Analysis Methods, & Additional Considerations
5. Summary6. Presentations from Sample Areas: XXXXXXXX7. Questions & Answers
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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.
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. Introduction2. Overview: Estimating GHG Emissions in the Planning Process3. What Methodologies are Applicable in Your Situation?4. Fuel-based Methods 5. VMT-based Methods6. Alternative GHG Estimation Approaches 7. Specific Transportation Strategy Analysis Methods8. Additional Considerations in GHG Analysis: Lifecycle Analysis
and GHG Emissions from Transportation Construction & Maintenance
9. References
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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 (CO2) Methane (CH4) Nitrous Oxide (N2O) 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.
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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.
Passenger Cars43%
Light-Duty Trucks19%
Medium- and
Heavy-
Duty Truc
ks22%
Air-craft8%
All Other Transportation
Sources6%
Ships and Boats2%
Factors affecting GHG Emissions from Transportation
External factors affecting travel
demand• Land use &
urban form• Fuel prices• Economic growth
Vehicle operations (speeds,
stops/starts, idling)
Transportation system investments and
strategies• Multimodal options• System quality• System management
and operations
Vehicle miles traveled (VMT)
Fuel Consumption
CO2 Emissions
Vehicle fleet• Composition (light-duty,
heavy-duty vehicles)• Characteristics (e.g., age)• Fuel type (e.g., gasoline,
diesel, electric)
Fuel economy
Carbon content of fuel
CO2 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
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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 CO2, N2O, and CH4
Fuel Consumed
Emission Factors
CO2 Emissions
GHGEmissions
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
What are the most appropriate methods to use?
Fuels and Vehicle Technologies
Fleet Mix Changes Vehicle Technology Changes Alternative Fuel Penetration
Type of Analysis and Time Frame
Inventory – year(s) Forecast – year(s)
Strategy Analysis – what specific strategies to consider
Geographic Scope
State Metropolitan Area
Local (i.e., city, county)
Analysis Precision Required
Regulatory/Compliance Approximate / Sketch
Plan
Modeling Capabilities Non-network-based approaches
Network-based 3-Step Travel Model Network 4-Step or Activity-based Model
Data Availability Motor Fuel Sales
HPMS, Travel Surveys, Odometer Surveys Roadway Speed Limits, Traffic Speed Surveys
Fleet Mix Data
Travel Demand Land Use Changes
Transportation Demand Management
Freight Flow Changes
Operations and Speed Factors
Traffic Congestion Levels Vehicle Idling
Speeds and eco-driving
Resources Available Staff Time
Budget
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Cross-cutting Factors to Analyze or Consider Fuel Prices
Population and Employment Levels Other Demographic and Economic Factors
Emissions and Sources to be Included
CO2 only or also CH4 & N2O
All transportation, on-road vehicles, or subset
Operational, lifecycle, construction & maintenance
Fuel-based Methods: An Overview
Fuel Consumed(e.g.,
gallons)
CO2 Emission
s
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• Only accounts for CO2, 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)
CO2 Emission
s
Common Data Sources: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)
CO2 Emission
s
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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 Fuel Emission FactorsKilograms CO2 Per
Unit of Volume
Kilograms CO2 Per
Million Btu
Aviation Gasoline 8.32 per gallon 69.19
Biodiesel
-B100 0 per gallon 0
-B20 8.12 per gallon 59.44
-B10 9.13 per gallon 66.35
-B5 9.64 per gallon 69.76
-B2 9.94 per gallon 71.80
Diesel Fuel 10.15 per gallon 73.15
Ethanol/Ethanol Blends
-E100 0 per gallon 0
-E85 1.34 per gallon 14.79
-E10 (Gasohol) 8.02 per gallon 66.30
-M100 4.11 per gallon 63.62
-M85 4.83 per gallon 65.56
Motor Gasoline 8.91 per gallon 71.26
Jet Fuel, Kerosene 9.57 per gallon 70.88
Natural Gas 54.60 per thousand cubic feet 53.06
Propane 5.74 per gallon 63.07
Residual Fuel 11.79 per gallon 78.80
Emissions Factors, available at: http://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
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SIT CO2 emissions factors were applied to calculate CO2 emissions
VMT-based Methods: An Overview
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VMT(miles)
Emission
Factors
(grams / mile)
GHG Emissi
ons
• Can be used to estimate CO2 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
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VMT(miles)
Emission
Factors
(grams / mile)
GHG Emissi
ons
• 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
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VMT-based Methods: Estimating VMT using HPMS Data or Network-based Travel Model
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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
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VMT(miles)
Emission
Factors
(grams / mile)
GHG Emissi
ons
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)
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For resources on using MOVES, see: 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
EPA’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
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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 information
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 Handbook38
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
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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
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Contact Information
Jody McCulloughFederal Highway Administration
Office of Planning1200 New Jersey Avenue SE
Washington, DC 20590