Chapter 13 - Energy

• Federal
• State

• Energy Categories
  • Direct Energy
  • Indirect Energy
• Energy Sources and Consumption
• Energy and Greenhouse Gas Emissions

• Determining the Need and Scope of a Separate Energy Analysis Report
• Preparer Qualifications
• Timing of Studies with the Environmental Process
• Report Content
  • Energy Analysis Report
  • Technical Memo
• Recommended Analysis Methods
  • Congestion Relief and Capacity-Increasing Projects
  • Non-Congestion Relief and Non-Capacity-Increasing Projects
• Information for Environmental Documentation
• Information Needed for Project Delivery
  • Project Initiation Document
  • Energy Analysis Report (or Technical Memo)
  • Draft and Final Environmental Document
• Permit Requirements

What Does This Topic Include?

This chapter discusses the policy and procedures regarding energy analysis, including when an Energy Analysis Report (or Technical Memo) is required for a proposed project.

Energy Policies and Regulations

Federal

NEPA (42 U.S. Code Part 4332) requires the identification of all potentially significant impacts on the environment, including impacts on energy resources. Guidance for evaluating energy impacts of transportation projects subject to NEPA is outlined in FHWA's Technical Advisory T6640.8A (Technical Advisory). The Technical Advisory energy analysis requirement applies to projects for which an Environmental Impact Statement (EIS) is prepared. The Technical Advisory indicates that documentation should discuss energy requirements for construction and operation, and the overall conservation potential for each of the project alternatives. The relationship of the project alternatives to applicable state or regional energy plan should also be documented. Additional conservation measures, such as use of high-occupancy vehicle incentives and other measures to improve traffic flow should also be identified.

Important issues of environmental protection are energy use, efficiency, and conservation. 40 CFR 1502.16 requires addressing in the discussion of environmental consequences:

1. 40 CFR 1502.16(a)(6) - Energy requirements and conservation potential of various alternatives and mitigation measures.
2. 40 CFR 1502.16(a)(7) - Natural or depletable resource requirements and conservation potential of various alternatives and mitigation measures.
   
   

The Energy Policy Act of 1992 aims to reduce dependence on petroleum and improve air quality by addressing all aspects of energy supply and demand, encourages the use of alternative fuels, renewable energy, and energy efficiency.

Other measures to improve energy efficiency in the transportation sector have been implemented at the federal level. The United States Environmental Protection Agency (U.S. EPA) and the National Highway Traffic Safety Administration (NHTSA) issued Final Rules governing Corporate Average Fuel Economy (CAFE) standards and other improvements to fuel economy to new vehicles. NHTSA's Corporate Average Fuel Economy (CAFE) standards regulate how far vehicles must travel on a gallon of fuel. NHTSA sets CAFE standards for passenger cars and for light trucks (collectively, light-duty vehicles), and separately sets fuel consumption standards for medium- and heavy-duty trucks and engines.

Further References

• Key Federal Legislation
• Department of Energy, Energy Information Administration
• National Highway Traffic Safety Administration, Corporate Average Fuel Economy

State

On December 28, 2018, the Governor's Office of Planning and Research and the California Natural Resources Agency updated the CEQA Guidelines to require that an Environmental Impact Report (EIR) include an analysis of a project's potential for significant environmental effects resulting from wasteful, inefficient, or unnecessary use of energy; or wasteful use of energy resources (Guidelines § 15126.2(b)). Appendix F, Energy Conservation, of the CEQA Guidelines outlines requirements for evaluating energy impacts of projects subject to CEQA. The appendix outlines criteria to consider in reviewing potential impacts, and places particular emphasis on “the wise and efficient use of energy” and “increasing reliance on renewable energy.”  An Initial Study (IS) must also examine potential energy impacts to determine if those impacts could be significant.  

The State has passed several bills directing state agencies and entities such as the California Energy Commission (CEC), California Air Resources Board (CARB) and the California Public Utilities Commission to implement renewable energy portfolio targets and energy efficiency measures to reduce energy consumption and GHG emissions in the state. These include but are not limited to Executive Order (EO) S-3-05 (June 1, 2005), Assembly Bill 32, Chapter 488 (2006), Executive Order B-30-15 (April 2015), Senate Bill 32, Chapter 249 (2016), and Assembly Bill 1279 (2022). What this means for California is an aggressive approach to decarbonize every sector of the economy through the aggressive reduction of fossil fuels wherever they are currently used in California.

In 2013, California’s “Advanced Clean Cars Program” was authorized by a waiver approved by U.S. EPA under a provision of the Clean Air Act that allows California to set and enforce vehicle emission standards more stringent than standards set by U.S. EPA. In 2019, California’s waiver authority to regulate GHG emissions was revoked and reinstated in 2022.

Beginning January 1, 2024, all California fleets subject to Section 2449.1(f) of the “Off-Road Regulation” (California Code of Regulations, Title 13, Sections 2449 et seq.) are required to procure and only use R99 or R100 renewable diesel fuel in all vehicles subject to the “Off Road Regulation,” with some limited exceptions. Caltrans, as a “Public Works Awarding Body” shall not enter into a contract with a prime contractor (including its subcontractors) that does not have a valid Certificate of Reported Compliance from CARB.

Further References

• AB 32 Global Warming Solutions Act of 2006
• California Air Resources Board, Low Carbon Fuel Standard 
• California Air Resources Board, Advanced Clean Cars Program
• California Energy Commission, Fuels and Transportation Division
• Amendments to the In-Use Off-Road Diesel-Fueled Fleets Regulation

Background

Energy Categories

Every activity results in energy consumption. Energy is either used for work (kinetic energy) or stored (potential energy). Kinetic energy is the amount of work necessary to move an object. In transportation, thermal energy from fuel combustion is converted into kinetic energy to propel vehicles. Electrical energy is used to power facilities such as highway lighting and to convert into heat for buildings.

The transportation sector consumes energy for all modes of transportation for people, goods, and services, such as automobiles, trucks, buses, trains, aircraft, and marine vessels. Transportation energy is generally separated into two main categories:  direct and indirect energy.

Direct Energy

In the context of transportation, direct energy involves all energy consumed by vehicle propulsion (e.g., automobiles, trains, airplanes). This energy consumption is a function of traffic characteristics such as vehicle miles traveled (VMT) (volume X distance traveled), speed, vehicle mix, and thermal value of the fuel being used.

Indirect Energy

Indirect energy is all the remaining energy needed to construct, operate, and maintain the roadway; and manufacture and maintain the vehicles using the roadway. Indirect energy is divided into two broad categories of central energy use and peripheral energy change. Central energy use encompasses the energy to manufacture and maintain vehicles, and construct, operate, and maintain the facility. Peripheral energy change addresses the potential effect that a transportation system may have on energy use and availability in the area it serves. For example, a highway can take agricultural land and, consequently, shift population and traffic patterns which in turn affect energy use (Caltrans 1983).

Fuel consumed by construction activities and equipment and vehicles required for periodic maintenance of the physical system associated with a project is considered indirect energy. The use of highway maintenance equipment and landscaping involve indirect consumption of energy after a facility is built. Street lighting is indirect energy needed in the operation of the highway. Special equipment and facilities may be needed for tunnels and bridges for their operation and may require the construction of maintenance buildings; indirect energy consumption of each tunnel and bridge and corresponding facilities may be unique and analyzed on a per project basis.

On a much larger scale, many energy users contribute indirectly to the energy consumption of a transportation system, but these are difficult to reliably quantify at the individual project level. These energy users include those that refine raw materials into products such as vehicles or roads; explore for and refine oil into various fuels; construct and maintain dams, power plants, transmission lines, fuel distribution systems, train stations, and airports; and many others. Such factors are often studied in energy life cycle or carbon footprint analyses. These considerations are important to acknowledge; however, attempting to characterize or quantify these factors at the project level is generally speculative and of little use to decision makers. As such, these factors are outside the scope of the project-level transportation energy analysis.

Energy Sources and Consumption

Transportation infrastructure in the United States was developed during a period of easy access to relatively inexpensive fossil fuels. The shock of an oil shortage in 1973 contributed to an awareness of petroleum as a finite resource that is ever diminishing as petroleum-based fuels are consumed around the world. Combustion of fossil fuels has also been linked to climate change. The dual concerns of potential energy shortages and environmental impacts of climate change have spurred legislative action at the federal and state levels as well as innovation geared toward conservation of existing fuel supplies, development of renewable fuels, and energy efficiency measures. A notable legislative act was the introduction of federal Corporate Average Fuel Economy (CAFE) standards in 1975 to mandate fuel efficiency improvements in motor vehicles, as discussed above under Energy Policies and Regulations.

Energy use in the transportation sector accounts for approximately 28% of total U.S. energy consumption in 2021. In California, the transportation sector accounts for approximately 33% of California’s total energy consumption. Though California is the most populous state, it had the fourth lowest per capita total energy consumption in the nation in 2021. California’s relatively low per capita energy consumption is due in part to the state’s robust energy efficiency policies and legislation. Energy consumption in California includes a mix of nonrenewable and renewable sources. By volume, the most consumed nonrenewable sources are natural gas, motor gasoline, and distillate fuel oil. Renewable resources include solar, wind, hydroelectric, nuclear, geothermal, and biomass (U.S. Energy Information Administration, 2023).

Figure 1 shows a graph of vehicle miles traveled (VMT) against fuel consumption from fuel retail sales. Data gathered have the following limitations: (1) VMT are only highway data (Caltrans), (2) Fuel consumption data are survey responses from retail fuel outlets that are required to report to CEC, with 2% to 5% estimated to be unresponsive (California Energy Commission). With these limitations, the trends and relationships are generalized for the larger population.

Figure 1. California Vehicle Miles Traveled and Fuel Retail Sales Volumes, 2010-2021

VMT -  https://dot.ca.gov/programs/research-innovation-system-information/highway-performance-monitoring-system

Retail Fuel Sales - https://www.energy.ca.gov/data-reports/energy-almanac/transportation-energy/california-retail-fuel-outlet-annual-reporting

As shown in Figure 1, prior to 2019, VMT is trending upwards and fuel consumption behavior of gasoline differs from that of VMT, with diesel and E85 flatter. After 2019 due to the COVID-19 pandemic, the graph shows a decline of VMT and gasoline but fuel consumption of diesel and E85 are still flatter. In 2020 when VMT was at its lowest value, consumption decreased for gasoline but increased for diesel and E85. Since there is no VMT data on local roads, the graph does not show the possible shorter trips that were made. Population and fuel prices may have an effect on consumption but are also not shown in this graph.

California's transportation energy consumption has become increasingly efficient due to technological growth, environmental policies, and innovation. Gasoline and diesel represent the largest fraction of fuel consumed by the transportation sector in California. To meet stringent emission standards, equipment and vehicle manufacturers install emission control systems to reduce emissions in addition to increasing engine efficiency. However, it is anticipated that CAFE regulations, Low Carbon Fuel Standard regulation, and zero-emission vehicle regulations will gradually displace gasoline and diesel engines in favor of more energy-efficient systems with lower GHG emissions.

The California Air Resources Board’s (CARB) diesel fuel regulation was originally geared to control criteria pollutant emissions but policies such as the federal Renewable Fuel Standards and California’s Low Carbon Fuel Standards (LCFS) created a market for alternative diesel fuel (CARB, 2023). In 2020 the United States consumed over 960 million gallons of renewable diesel and nearly all domestically produced and imported renewable diesel is used in California due to economic benefits under the Low Carbon Fuel Standard (U.S. DOE Alternative Fuels Data Center). As of early 2022, there were only 6 renewable diesel refineries in the country but by 2030 the number of refineries is estimated to increase to 25 (Caltrans, 2022).

Due to Renewable Fuel Standards and the Energy Policy Act (EPAct) of 1992, ethanol as a transportation fuel grew rapidly in the 2000s. Growth in ethanol use leveled off but continued to increase at a slower rate after 2010 due to the expiration of a federal tax credit for ethanol blenders (U.S. Energy Information Administration 2021). Despite the slowing rate of growth, most gasoline in the United States is still blended with 10% ethanol fuel by volume (U.S. Energy Information Administration 2021). Nationwide, the only decrease in ethanol use in recent history was in 2020 due to the COVID-19 pandemic causing supply chain issues and dramatically reducing vehicle travel and fuel consumption (National Renewable Energy Laboratory 2023). E85 consumption in California continued to rise even after 2019 per survey responses of fuel stations, as shown in Figure 1 (California Energy Commission).

Energy and Greenhouse Gas Emissions

Combustion of fossil fuels such as gasoline and diesel produce GHGs such as carbon dioxide (CO2), methane (CH4), nitrous oxide (N2O), and smaller amounts of other GHGs, which contribute to atmospheric warming.

Project-level analyses of energy and GHG emissions use similar data to derive project emissions or energy consumption. However, energy and GHG emissions are distinct resource areas accounting for different types of environmental impacts. Energy in a resource context generally pertains to the use or conservation of fossil fuels, which are a finite resource. GHG studies, on the other hand, describe the potential of a project to contribute to climate change. Because each of these resource areas address different environmental concerns, both are studied in evaluation of overall environmental effects.  The SER, Volume 1, Chapter 16 – Climate Change, contains separate guidance for assessing effects and quantifying construction and operational GHG emissions at the project level.

Further References

• Energy Requirements for Transportation Systems (PDF)

Interagency Coordination

Caltrans has primary oversight of the energy analysis for both state-only projects and federally-funded projects. For further guidance, see SER Volume 1, Chapter 38, NEPA Assignment.

Most Metropolitan Planning Organizations (MPOs) or Regional Transportation Planning Agencies (RTPAs) will conduct their own energy analysis as part of the environmental document prepared for their Metropolitan Transportation Plans (MTP) or Regional Transportation Plan (RTP) and Sustainable Communities Strategy (SCS), as applicable. Cities and other jurisdictions prepare climate action plans and energy-efficiency plans that may contain strategies and measures to reduce transportation energy consumption.

Information contained in the environmental document for an MTP/RTP/SCS and other local plans will be needed to determine that a proposed project does not obstruct or conflict with a state or local plan for renewable energy or energy efficiency.

Energy Analysis Report

Determining the Need and Scope of a Separate Energy Analysis Report

For NEPA, an Energy Analysis Report (EAR) with a quantitative energy analysis will only be required when an EIS is prepared, and the project is a large-scale project with potentially substantial energy impacts. For an EIS that is not a large-scale project with potentially substantial energy impacts, an EAR with a combination of qualitative and quantitative analysis or a Technical Memo is sufficient. If an EAR has been prepared to comply with CEQA, the results of that study can be included in an Environmental Assessment or EIS prepared for NEPA.

For CEQA, an EAR with a quantitative energy analysis is required for projects that require an Environmental Impact Report (EIR) or Initial Study/Negative Declaration/Mitigated Negative Declaration (IS/ND/MND) and relieve congestion or increase capacity. For non-capacity increasing and non-congestion relief projects that require an EIR or IS/ND/MND, an EAR with a combination qualitative and quantitative analysis or a Technical Memo is sufficient. If a CEQA Exemption is being prepared, ensure that the project does not have the potential for significant energy impacts (i.e., unusual circumstances), which would preclude the use of a CE.

Refer to the Energy Analysis Report Decision Tree (PDF) | ADA Version (PDF) for additional information.

Table 1 summarizes the required documentation and scope for the energy analysis based on the environmental document type and project characteristics. 

Note: An EAR should consider section 15126.2(b) and Appendix F of the CEQA Guidelines, “Energy Conservation” for both short-term and long-term impacts. Construction control measures chosen should be included in the project’s contract specifications so that commitments listed in the Environmental Commitments Record (ECR) can be met.

Preparer Qualifications

There are no specific preparer qualifications for an Energy Analysis Report (or Technical Memo). Because of the overlap in data needs between the Air Quality Report (AQR) and the energy study, the Energy Analysis Report may be best prepared by an environmental engineer.

Timing of Studies with the Environmental Process

Information from the Energy Analysis Report (or Technical Memo) will be summarized in the draft environmental document; therefore, the Energy Analysis Report (or Technical Memo) must be completed prior to completing the draft environmental document. To the extent that the proposed project is modified or new information is obtained after circulation of the draft environmental document, the energy analysis may need to be revised prior to completion of the final environmental document.

Report Content

Energy Analysis Report

The Energy Analysis Report describes the proposed project's regulatory and environmental settings, the environmental consequences, and measures to avoid, minimize, and/or mitigate adverse impacts of the project on energy resources.

An Energy Analysis Report should be organized as follows.

• Executive Summary, describes an overview of the major points of the results, conclusion, and recommendations.
• Chapter 1, Project Description, describes the project's characteristics, including location, purpose, need, the alternatives, and construction schedule.
• Chapter 2, Regulatory Setting, describes current federal, state, and local energy regulations, policies, and legislation.
• Chapter 3, Affected Environment, provides background information on state and local energy resources and usage. This section should also include a description of existing conditions in the project area that affect energy usage. For example, what are the existing traffic conditions? What mix of vehicles is currently using the facility (particularly if the project is expected to substantially change the vehicle mix)? Are there existing traffic management system (TMS) elements in place? What is the condition of the existing pavement surface? A poor driving surface can contribute to an increase in fuel consumption. Is there existing highway lighting and what type is it?
• Chapter 4, Environmental Consequences, discusses study methods and required models; presents the results of the energy analysis and discloses potential energy effects, including project consistency with applicable federal, state, and local energy regulations, policies, and legislation. This section should also evaluate energy consumption changes due to specific project features, for example, travel mode shift from traveling by water (ferry) to traveling by land (bridge). This section should also include any energy-saving or conservation measures specifically incorporated into the design of the project. The analysis in this section is subject to the rule of reason and shall focus on energy use that is caused by the project—a full "lifecycle" analysis that would account for energy used in building materials and consumer products will generally not be required as this will be outside the scope of the project-level transportation energy analysis.
  
  Energy conservation features incorporated in the project design should be described in the EAR or Technical Memo. Below are some examples of these features:
  • Pavement Strategies, Rehabilitation/Maintenance. Materials influence the fuel economy of vehicles traveling on the highway system. Smoother pavements not only ensure safer highway networks, but also help reduce pavement-vehicle tire friction, and thereby reduce overall fuel consumption (Caltrans 2020).
  • Roundabouts improve safety, increase accessibility to non-motorized traffic and reduce delay resulting in reduction of fuel consumption. It also reduces indirect energy consumption by reducing maintenance activities due to collisions (Caltrans).
  • Transportation Systems Management and Operations (TSMO) is a set of strategies that focus on operational improvements that can maintain and even restore the performance of the existing transportation system before extra capacity is needed. The goal is to get the most performance out of the existing transportation facilities (FHWA).
  • LED lights use up to 90% less energy and last up to 25 times longer than traditional incandescent bulbs (U.S. Department of Energy).
    
    
  Further References:
  • Caltrans Greenhouse Gas Emissions and Mitigation Report (found under the Technical Resources, Tools and Training tab)
  • Vehicle Fuel Consumption and Pavement Characteristics
  • Roundabout Benefits
  • Transportation Systems Management and Operations (TSMO)
  • Lighting Choices to Save you Money
  • Transportation Energy and Climate Change Strategies
    
    
• Chapter 5, Avoidance, Minimization, and/or Mitigation Measures, discusses proposed environmental commitments.
• Chapter 6, Conclusions, summarizes the long-term (operations and maintenance) and short-term (construction) project impacts and/or conservation of energy resources.
• Chapter 7, References Cited, lists the printed references and personal communications used to prepare this report.
• Appendices, presents the results of the modeling tool used in the analysis.
  
  

There are no formalized processing requirements for the Energy Analysis Report. However, the draft Energy Analysis Report should be reviewed by the environmental generalist, the project manager, and the project engineer at a minimum. Following the Caltrans internal review of the draft, the Energy Analysis Report may be finalized.

Technical Memo

The Technical Memo simplifies the Energy Analysis Report. The Technical Memo is used for both NEPA (EIS) and CEQA (IS/ND/MND) when an EAR is not required, as shown in Table 1. Energy analysis results are summarized, and control measures chosen will be included in the environmental document.

The GHG interim guidance requires quantitative construction GHG analysis for all projects and the latest CAL-CET version will also estimate fuel and electricity consumption, these estimates will be available for the Technical Memo. Therefore, at a minimum, the Technical Memo should have quantitative analysis for construction. Chosen construction control measures should be included in the project’s contract specifications so that commitments listed in the Environmental Commitments Record (ECR) can be met.

A Technical Memo should be organized as follows.

• Project Description, describes the project's characteristics, including location, purpose, need, and the alternatives.
• Affected Environment, provides background information on state and local energy resources and usage, as well as current federal, state, and local energy regulations, policies, and legislation. This section should also include a description of existing conditions in the project area that affect energy usage.
• Study Methods, describes the method used to analyze project-level energy effects. Current approved versions of emission tools should be used to quantify energy consumption, such as latest versions of EMFAC, CT-EMFAC or CAL-CET.
• Environmental Consequences, presents the results of the energy analysis and discloses potential energy effects, including project consistency with applicable federal, state, and local energy regulations, policies, and legislation. This section should also include any energy-saving or conservation measures specifically incorporated into the design of the project. This section should also discuss any required avoidance, minimization, and/or mitigation measures that will be included in the Contract Specifications. Project feature examples that reduce energy consumption are described above.
• Conclusions, summarizes the long-term (operations and maintenance) and short-term (construction) project impacts and/or conservation of energy resources.

Recommended Analysis Methods

The scope of the energy analysis for long-term impacts should be based on the anticipated impact the project will have on energy use (see Table 1 above). The degree to which a project impacts energy is often heavily influenced by its potential to reduce congestion or increase capacity. Projects that increase capacity or reduce congestion are more likely to result in material or permeant changes to energy use when compared to non-capacity-increasing and non-congestion relief projects.

Examples of congestion relief and capacity-increasing projects include the following.

• New Roadway or Facility: Bypass, new or extended highway, new interchange
• Additional Lanes: HOV lanes, general purpose/mixed flow lanes, managed, express, and toll lanes
• Interchange Reconfiguration: ramp widening or increased through lanes on bridges
• Auxiliary lanes 1 mile or more in length
  
  

Examples of non-congestion relief and non-capacity-increasing projects include the following.

• Ramp metering or signalization
• Auxiliary lanes less than 1 mile in length and independent from other auxiliary lanes
• Increase shoulder width
• Pavement rehabilitation
  
  

As shown in Table 1, when an EIR or IS/ND/MND is prepared under CEQA, congestion relief and capacity-increasing projects will require a quantitative assessment of energy impacts. When an EIS is prepared under NEPA, large-scale projects with potentially substantial energy impacts will require a quantitative assessment of energy impacts. As noted above, projects that increase capacity or reduce congestion are more likely to have substantial energy impacts, and thus require a quantitative assessment.

A substantial energy impact should be evaluated on a per project basis as it will differ according to the size and type of project and even within the same mode of travel. Alternatives may also vary as to their direct and indirect energy consumption. Examples below:

• A highway widening project that will add an HOV lane both ways for 20 miles may have substantial energy impacts. The 20-mile highway widening will mean; (1) adding or replacing auxiliary lanes to accommodate the proposed new lanes at interchanges, (2) new onramp/offramp, as needed, (3) new soundwalls, (4) new retaining walls, etc. Alternatives must be evaluated if these will result in a substantial increased use of energy. Construction and maintenance energy consumption must be evaluated against energy being saved by relieving congestion and efficiencies introduced by transportation system management and operation strategies. Other project features such as change in speed limits and change in vehicle occupancies (if applicable), should be evaluated.
• A new highway may have substantial energy impact because existing conditions (without a highway) will not consume energy.
• A tunnel replacing an existing roadway may have substantial energy impact because though it may cut the distance and grade traveled by vehicles (reducing direct energy consumption) it will require more indirect energy to construct than a more circuitous route and will need facilities (e.g., maintenance building) and more maintenance cycles needed to operate.
• A new bridge replacing a ferry crossing may have substantial energy impact because ease of access may increase traffic volume (more direct energy consumed) and more indirect energy consumed to construct and maintain. The change of modes must also be evaluated; (1) from ferries using diesel to cars and trucks using gasoline, diesel, electricity, etc., (2) port to port energy consumption versus land travel energy consumption.
  
  

Specific analysis methods by project type (e.g., congestion relief, capacity-increase) are outlined below.  All EARs (or Technical Memos), regardless of the project type, should evaluate energy from vehicles using the facility (i.e., fuel consumption) and ongoing uses of energy such as roadway lighting, as well as energy consumption from new facilities (e.g., transit centers or maintenance stations). Vehicles and equipment associated with maintenance of the facility are considered permanent indirect energy users. Construction is a temporary and one-time indirect user of energy and should be evaluated as well, refer to Table 1.

Congestion Relief and Capacity-Increasing Projects

Congestion relief and capacity-increasing projects affect the ability of a transportation facility to accommodate existing and future traffic demand. This results in changes to direct energy consumption (i.e., fuel usage) by vehicles using the facilities. Congestion relief and capacity-increasing projects require construction, which is a one-time indirect energy user that ceases to consume energy once work is complete. Some projects may also include new buildings or more roadway lighting, which will consume energy continuously. Maintenance and landscaping activities would result in long-term indirect energy consumption through the use of equipment required to maintain the facility and associated facilities. Electricity usage in buildings or roadway lighting can generally be discussed qualitatively, as can the energy requirements of long-term maintenance of the facility, as discussed further below.

Direct Energy (Operations): The basic procedure for analyzing direct energy consumption by vehicular traffic is to calculate fuel consumption using CT-EMFAC. CT-EMFAC is an emission tool developed by Caltrans that calculates project-level emissions and fuel consumption using data from the California Air Resources Board's EMFAC model (latest approved version). 

Indirect Energy (Construction): The basic procedure for analyzing indirect energy consumption from construction activities is to obtain fuel consumption projections in gallons and electricity used in kWh from the Caltrans Construction Emission Tool (CAL-CET). CAL-CET outputs both emissions and energy consumption based on project-specific construction information. If a different emission tool is used and energy consumption data are not available, fuel consumption may be converted from CO2 emissions generated by diesel and gasoline powered equipment using the U.S. EPA equivalencies formulas for gasoline and diesel. These CO2 emissions can be obtained from the Air Quality Report or GHG analysis, where they may have been quantified using the latest version of CalEEMod.

It is preferable to break out construction fuel consumption by fuel type (e.g., gasoline, diesel, natural gas), as the carbon content differs between types of fuels. Gasoline is typically used for employee commute vehicles (e.g., light-duty vehicles and trucks) and smaller construction equipment pieces (e.g., tampers and mowers). Diesel is typically used for off-road construction equipment (e.g., graders, dozers) and heavy-duty trucks. Electricity, natural gas, or other alternative fuels may also be consumed by equipment and vehicles. Fuel volumes can be converted to the British thermal unit (Btu) which is a measure of the heat content of fuels.

Indirect Energy (Maintenance): Maintenance and landscaping activities would result in long-term indirect energy consumption through the use of equipment to maintain the project and associated facilities. Roadways will require periodic maintenance, which could result in indirect energy consumption from equipment and vehicles. Generally, these impacts can be discussed qualitatively but if information is available from design or maintenance, then a quantitative analysis can be done.

Indirect Energy (Operations): For vehicle safety, roads will need traffic lights, streetlights, changeable message signs (CMS), etc., and these will result in long-term indirect energy consumption. Operation of tunnels and bridges may need continuous monitoring, lighting, and ventilation that may need a dedicated maintenance building which will result in energy consumption for both tunnel or bridge and building. Rest areas open to the public will use electricity to illuminate its facilities. Rest areas that have large open areas have an option to use solar energy and provide charging stations. Indirect energy impacts due to operation of the transportation system may be discussed qualitatively but if information is available, then a quantitative analysis can be done.

Non-Congestion Relief and Non-Capacity-Increasing Projects

A qualitative discussion of energy usage will normally suffice for non-congestion relief and non-capacity increasing projects, although a combination approach can be used if data is available to support energy quantification. GHG construction emissions are calculated for all projects using CAL-CET, and the output will include an estimate of energy consumption which can be used for energy analysis. Fuel consumption can also be converted from estimated CO2 emissions using the U.S. EPA equivalencies, as discussed above.

Many non-capacity increasing projects may contribute to roadway improvements that would reduce emissions and energy consumption. For example, a pavement project may result in smoother pavement surfaces, which would improve vehicle operations and reduce emissions and energy consumption. Transportation Management Systems (TMS) infrastructure including Intelligent Transportation Systems (ITS) components such as traffic signals, ramp meters, changeable message signs, and real-time traffic monitoring can improve traffic flow without increasing the capacity of the highway. If traffic data is available for a project incorporating TMS elements, direct energy consumption may be assessed quantitatively across project alternatives. Traffic data could include average vehicle speed, vehicle delay, level-of-service, volume-to-capacity ratios, and idling time. A comparison between these factors could allow for an evaluation of relative fuel consumption levels between alternatives, depending on how efficiently vehicles would be able to travel through the system.

The effect of the speed of vehicles traveling through a roadway system may also be appropriate to consider in a qualitative analysis. Average fuel economy as a function of speed is shown in Figure 2 below. In general, there is an optimum traveling speed that will allow vehicles to use fuel more efficiently. Projects that improve traffic flow during peak travel demand periods or reduce stop-and-go conditions would improve vehicles' fuel economies, and thus affect project energy consumption.

Figure 2. Fuel Economy by Speed
https://www.fueleconomy.gov/feg/driveHabits.jsp, U.S. Department of Energy.

Another important consideration is that for operation of a project over the long-term, newer and more fuel-efficient vehicles (including alternative fuel types and technology) will enter the fleet, resulting in an overall lower potential for an increase in energy consumption due to vehicle traffic. Additionally, projects that include elements that would reduce VMT, such as transit improvements or providing facilities for pedestrians and bicyclists, would generally offset some of the project's potential energy usage. Projects that directly support the use of electric vehicles, such as the installation of charging stations, would also reduce gasoline and diesel usage. All-electric vehicles (EVs) convert over 77% of the electrical energy from the grid to power at the wheels. Conventional gasoline vehicles only convert about 12% - 13% of the energy stored in gasoline to power at the wheels (U.S. Department of Energy).

Figure 3 shows that efficiency improvement of battery electric vehicles is considerably higher than conventional diesel vehicles for different weight classes, vehicle types, and duty cycles. The vehicle energy efficiency ratio (EER) is about 3.5 at highway speeds and 5 to 7 times the efficiency of conventional diesel vehicles when operated at lower speed duty cycles where idling and coasting loses from conventional engines are highest (CARB, 2018).

Figure 3. Vehicle Energy Efficiency Ratio at Different Average Speeds

https://ww2.arb.ca.gov/sites/default/files/2018-11/180124hdbevefficiency.pdf, California Air Resources Board.

Information for Environmental Documentation

The Environmental Consequences section should specifically address whether the project may result in wasteful, inefficient, or unnecessary consumption use of energy, or wasteful use of energy resources. The guidance in section 15126.2(b) and Appendix F of the CEQA Guidelines, Energy Conservation, should also be considered. Note that there is a focus on energy efficiency, savings, and conservation in the CEQA guidance. This is a good place to demonstrate a project's long-term potential for energy savings (if applicable) and to document conservation measures to be employed during the construction, operation, and maintenance phases. Both an EIR and an IS/ND/MND require a discussion of energy impacts. An EIR must include an analysis of energy use and must provide mitigation for significant effects if the project has the potential for a significant effect related to energy.

A discussion of environmental consequences should consider changes in total direct and indirect energy consumption under project build alternatives relative to existing conditions and the no-build alternative(s). For example, a transportation improvement energy study is very likely to indicate that construction of the improvements would result in a temporary increase in energy consumption. However, this may be offset over time by improvements in the form of altered traffic patterns or traffic flow, resulting in overall reduced energy consumption relative to the no-build condition.

Many projects will result in energy savings. As noted above, projects that make roadway improvements or that smooth existing traffic flow may result in reduced energy consumption. Projects that reduce VMT or incorporate active transportation elements may also lower or partially offset energy consumption. Replacing older highway lighting with newer energy efficiency lighting can result in energy savings over the long term. Projects that reduce out-of-direction travel like improvement of signage can also lessen energy consumption. Indirect energy savings through reduced maintenance needs (roadway, culverts, etc.) should also be discussed.

Another factor to discuss in the context of environmental consequences is future energy efficiency improvements in the vehicle fleet due to gradual implementation of federally-mandated and California regulations on fuel efficiency standards. This would result in a net reduction of energy consumption over time. The analysis tools that quantify fuel and emissions from vehicles and equipment account for legislatively adopted vehicle fuel efficiency standards.

A discussion should include any energy-saving measure specifically incorporated into the project design. This could include reduction in grades and curvatures, and use of renewable energy sources in construction and operation of the project. Other examples might include the use of recycled materials, LED lighting, solar power, or the installation of TMS elements.

The discussion of environmental consequences must also describe the applicable Regional Transportation Plan (RTP) and other planning documents in order to demonstrate that the project does not obstruct or conflict with a state or local plan for renewable energy or energy efficiency.

Information Needed for Project Delivery

Project Initiation Document

Consideration of potential energy impacts should begin as early in the project development process as possible.

Projects on the State Highway System (SHS) – The need for an energy study should be determined at the Project Initiation stage and discussed in the Preliminary Environmental Analysis Report (PEAR). When preparing the energy portion of the PEAR, points to consider include: 1) whether an energy analysis is needed for the proposed project; and 2) if an energy analysis is needed, what would be the proper scope of the analysis?

Energy Analysis Report (or Technical Memo)

As discussed above, the Energy Analysis Report (or Technical Memo) must be completed prior to completion of the draft environmental document and draft project report. The potential energy impacts of each alternative should be analyzed and discussed in the environmental document along with any proposed avoidance, minimization, and/or mitigation measures.

The Energy Analysis Report (or Technical Memo) may be revised after circulation and public comment on the draft environmental document. To the extent that the proposed project is modified, or new information is obtained after circulation of the draft environmental document, the energy analysis may need to be revised prior to completion of the final environmental document.

Draft and Final Environmental Document

Refer to “Information Needed for Environmental Documentation” section above.

Permit Requirements

There are no permits required with respect to potential energy impacts.

(Last content update: 10/26/2023)