In recent years, the transportation sector has overtaken the electric power sector as contributing the most to greenhouse gas emissions in the United States. Between 1990 and 2018, emissions from the transportation sector increased more than any other sector, in part due to a steady increase in the number of auto vehicles used by households and for the shipment of domestic and international goods. Meanwhile, the renewable energy and natural gas industries have grown tremendously over the past two decades, greatly reducing GHG emissions from the electric power sector, historically one of the largest contributors to carbon pollution. With renewable energy predicted to continue expanding, there is increased attention on reducing emissions from the transportation sector, which now contributes 29% of total GHG emissions in the United States.
Besides carbon emissions, the transportation sector also contributes to air pollutants such as nitrogen oxides (NOx), volatile organic matter (VOCs), and particulate matter (PM), all of which have negative impacts on people's health and well-being. Additionally, continued road-building leads to further habitat destruction, and in many cases, it represents discriminatory planning that has physically separated minority communities and contributed to unequal health impacts within them.
While the transportation sector contributes the most to US emissions compared to other economic sectors, the main culprits are medium- and heavy-duty trucks and light-duty vehicles. Collectively, these three categories of vehicles contribute over 80% of emissions from the entire transportation sector.
The transportation sector's contribution to emissions should come as no surprise considering there are over 280 million registered vehicles in the country. Over 90% of households have access to a vehicle, more than 51 million tons of goods move daily across the United States, and the trucking industry alone provides ~6% of full-time jobs in the country.
Reducing emissions from the transportation sector may be even more challenging than reducing emissions from the electric power sector. Some of the challenges ahead include: switching to cleaner fuel sources, changing consumer consumption habits, developing more robust public transportation systems, and redesigning our communities and cities. Overcoming these obstacles may take years of effort, years that the planet may not have.
Electric vehicles (EVs) represent one of the most encouraging solutions to reduce emissions from the transportation sector. Relying only on batteries for propulsion, EVs produce no direct emissions or air pollution, and the main source of related emissions comes from the electricity that powers them.
EV success depends on further battery improvements that will boost vehicle performance and lower prices. Continued battery R&D has helped bring down battery prices, making EVs more efficient and affordable. EVs have greatly benefited over the last decade as R&D and the increase in battery production have brought battery prices down 85% from $1,100/kWh in 2010 to now under $150/kWh. While EV ownership is still low, EVs are expected to achieve cost parity with conventional gasoline vehicles in 3-5 years, and EV ownership will increase accordingly.
Even though electric vehicles will better the environment, they should not be viewed as a panacea for climate change. Currently, most support seems to be towards solutions like EVs that do not challenge the American way of life. But maybe we need to be more ambitious. Public transportation is more fuel-efficient and produces drastically fewer emissions. Concepts such as "complete streets" or "15-minute cities" provide increased access to alternative modes of transportation and reduce the need for automobiles. These types of solutions are also much more equitable and will ensure that everyone, regardless of socio-economic status, can participate in a cleaner transportation system.
If you are interested in learning more about sustainable transportation systems, electric vehicles, and other transportation solutions, I encourage you to explore the resources below!
The general resources below provide introductory information on alternative transportation solutions, particularly electric vehicles. They will help you understand how these technologies work and how they can be put to use to reduce emissions and provide additional services to society.
Models and Simulators
There are many free calculators online with which you can use to determine the carbon emissions related to your vehicle and driving habits, assess emission rates between different vehicle types, and compare the fuel costs between EVs and gasoline. There are more sophisticated models and calculators available with which you can assess vehicle environmental impacts, driving cycles, markets, and technology improvements.
Stochastic Energy Deployment System
Long-range model for US energy markets used to explore how the energy economy will respond to the development of new technologies
EV Infrastructure Projection Tool Lite
Simple tool that estimates how much electric vehicle charging you might need and how it affects your charging load profile
Analytical tool that simulates the energy use and emissions output of various vehicle and fuel combinations, capturing the full life cycle
Emission modeling system that estimates emissions for mobile sources at national, county, and project level for criteria air pollutants, GHGs, and air toxics
GHG Emissions Model for Medium and Heavy Duty Vehicle Compliance
Application that estimates the GHG emissions and fuel efficiency performance of specific aspects of heavy-duty vehicles
EV Carbon Calculator
Simple calculators that enables you to compare CO2 emissions for gas and electric cars over a year of driving
Electric Vehicle Calculator
Calculator that can help EV buyers and existing owners understand the true environmental impact of EVs in their region
Fuel and Emissions Calculator
Calculator that makes it easier for transit agencies to assess and compare the performance of alternative vehicle technologies
Petroleum Reduction Planning Tool
Simple tool that allows you to create a comprehensive plan to reduce your vehicle fleet fuel consumption and emissions
Simple calculator that compares the cost of gasoline with the cost of a "gallon" worth of electricity for EVs
Energy Calculator Widgets
Different cost calculators for vehicles of different fuel type
Drive-Cycle Rapid Investigation, Visualization, and Eval. Analysis Tool
Analysis tool that produces representative drive cycles from large amount of vehicle data
Drive Cycle Analysis Tool
Tool that provides drive cycle data based on real-world vehicle operation for modeling, simulation, and evaluating advanced vehicle systems
Future Automotive Systems Technology Simulator
Tool that provides a simple way to compare powertrains and estimate the impact of technology improvements on vehicle efficiency, performance, cost, and battery life
Automotive Deployment Options Projection Tool
A light-duty consumer choice and stock model which estimates technology improvements on future light-duty vehicle sales, energy use, and emissions
Electric Vehicle Infrastructure - Financial Analysis Scenario Tool
Tool that provides quick and convenient, in-depth financial analysis for electric vehicle charging infrastructure
Argonne AFLEET Tool
Combination of four different tools that examine the environmental and economic costs of alternative fuel vehicles.
Databases and Browsers
Below are some databases and data browsers with information on alternative fuel vehicle models, electric mobility policies, and charging station locations. For those more interested in research, check out Fleet DNA or the Transportaiton Secure Data Center.
Alternative Fuel Vehicle Data Browser
EIA data browser on alternative fuel vehicles
Alternative Fueling Station Locator
DEO database of alternative fueling stations (electric, hydrogen, CNG, etc.) and their location across the US and Canada
Charging Station Map and Trip Planner
Database of electric charging stations and their locations which can be incorporated into trip planning
Information on past, existing, and planned policies and measures to reduce emissions, improve efficiency, and support clean energy technologies
Find Electric Vehicle Models
DOE electric vehicle search engine
Alternative Fuel and Advanced Vehicle Search
DOE search engine for alternative fuel vehicles, engines, and hybrid/conversion systems
AFDC Maps and Data
DOE repository of maps and charts showing transportation data and trends related to alternative fuels and vehicles
The Global Electric Vehicle Policy Database
UNEP databases with information on fiscal, regulatory and other electric mobility related policies in countries around the world
Fleet Sustainability Dashboard
DOE database that monitors compliance with EPAct 2005 Section 701 and tracks participating agencies' fuel consumption, emissions, and inventories
Fleet DNA: Commercial Fleet Vehicle Operating Data
Clearinghouse of commercial fleet vehicle operating data which can help fleet managers choose advanced technologies for their fleets
Transportation Secure Data Center
Database that provides access to detailed transportation data from a variety of travel surveys and studies
The following reports and papers cover electric vehicles, sustainable fleets, and other transportation solutions, such as sustainable aviation fuel and biofuels. If you have other topics that should be covered or other papers that should be added, submit a comment at the bottom of the page.
This video breaks down the important mechanical components that power and operate electric vehicles.
This video looks at hydrogen fuel cells and the utility of hydrogen as a replacement fuel for fossil fuels.
This video discusses the environmental impacts of the aviation industry, the challenges of reducing aviation emissions, and some of the potential solutions.
V2G could support the mass adoption of electric vehicles while mitigating the impact of increasing electrical loads on the grid. This video explains how V2G could benefit the grid, the environment, and customers.
This video reviews the different types of biofuels and their potential to replace fossil fuels. It also discusses the drawbacks of heavily relying on biofuels.
This video breaks down the differences between China and the US in the adoption of electric buses. It also analyzes different electric bus programs in the US.