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

2

HANDBOOK OVERVIEW

3

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. 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

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 (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.

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.

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.

GHG ANALYSIS IN THE PLANNING PROCESS

14

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 AND TOOLS

17

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

: KDWLVWKHJRDORIWKHDQDO\ VLV"

: KDWGDWDWRROVDQGUHVRXUFHVGRZ HKDYHDYDLODEOH"

: KDWYDULDEOHVGRZ HZ DQWWRDQDO\ ] H"

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

21

Fuel-based Methods: An Overview

Fuel Consumed(e.g.,

gallons)

CO2 Emission

s

22

• 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

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 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

26

SIT CO2 emissions factors were applied to calculate CO2 emissions

VMT-BASED METHODS

27

VMT-based Methods: An Overview

28

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

29

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

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 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)

33

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

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.

OTHER APPROACHES

36

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

39

SUMMARY

40

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 McCulloughFederal Highway Administration

Office of Planning1200 New Jersey Avenue SE

Washington, DC 20590

Jody.McCullough@dot.gov202-366-5001