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U.S. Department of Transportation U.S. Department of Transportation Icon United States Department of Transportation United States Department of Transportation

Public Roads - Winter 2018

Winter 2018
Issue No:
Vol. 81 No. 4
Publication Number:
Table of Contents

Refueling America

by Diane Turchetta, Carter Purcell, and Sean Nyhan

FHWA is shaping the future of highway infrastructure by designating corridors across the country that provide charging and fueling stations for vehicles powered by electricity, hydrogen, propane, and natural gas.


Minnesota Department of Transportation

Signage for alternative fueling corridors, like these roadside signs marking the beginning of such a corridor in Minnesota, is poised to go up along sections of the National Highway System, increasing mobility and access for drivers of alternative fuel vehicles.


Alternative fuel vehicles are now more common than ever. According to the 2017 Fuel Economy Guide published by the U.S. Department of Energy and the U.S. Environmental Protection Agency, consumers can now find a variety of alternative fuel vehicles on the market. With more than 23,000 public facilities located throughout the United States to charge and fuel those vehicles, they are becoming a more viable choice for commercial and passenger vehicles. However, a challenge remains: how can this market continue to grow without adequate infrastructure to keep these vehicles fueled and charged? For stakeholders waiting for alternative fuel vehicles to evolve from automotive novelties to ubiquitous commercial and passenger vehicles, a common refrain echoes out over the miles and miles of highways without adequate fueling stations: If you build it, they will come.

Forecasts for sales of alternative fuel vehicles will likely fluctuate in the coming years depending on the steps taken by State and local officials to connect the dots between available fueling stations. After all, consumer research points to a direct connection between fuel availability and attitudes about alternative fuel vehicles. Take electric vehicles (EVs), for example. With recent improvements in battery technology, EV drivers can travel increasingly long distances on a single charge. But concern over both the availability and the convenience of access to charging stations may trigger a phenomenon known as range anxiety in EV drivers.

To address the missing pieces, the Federal Highway Administration is supporting a series of nominations to designate alternative fueling corridors along sections of the National Highway System. As part of the Fixing America’s Surface Transportation (FAST) Act, FHWA has solicited submissions from State and local officials across the country to identify candidate corridors. According to the solicitation, the designations must identify the need for fueling infrastructure at strategic locations along major national highways to improve the mobility of passenger and commercial vehicles that employ electric, hydrogen fuel cell, propane, and natural gas fueling technologies across the United States. FHWA is also supporting testing technologies that may charge EVs while they are in motion on interstate highways (via electrically charged magnetic coils embedded in or on the surface of the pavement).

“The corridors developed by FHWA are an innovative way to improve infrastructure and mobility for alternative fuel users across the Nation,” says Gloria Shepherd, associate administrator of FHWA’s Office of Planning, Environment, and Realty. “By making these fuels accessible, FHWA also helps to promote U.S. energy security and strengthen our economy by reducing dependence on foreign oil.”

Creating a National System

As part of the FAST Act, the U.S. Department of Transportation is required to identify aspirational goals to be met by 2020 for the deployment of domestically produced electricity, hydrogen, natural gas, and propane fueling infrastructure. One such goal is the incorporation of consistent signage throughout the corridor. To date, corridors in 35 States plus Washington, DC, have been designated as signage-ready, which means enough facilities exist on the corridor to warrant signage alerting drivers of the availability of alternative fueling stations.

Fuel Types in the Alternative Fuel Corridor Program

tur2EV charging. A form of fueling for plug-in electric drive vehicles, EV charging involves pulling energy from an offboard power source. This category includes both hybrids (10–50 miles, 16–80 kilometers, on a single charge) and fully electric vehicles (60–300 miles, 96–482 kilometers). The market is strongest along the west coast, in the Northeast, and in Hawaii.

Hydrogen. This gaseous alternative fuel can come from natural gas and other types of renewable electricity. Hydrogen fuel cell electric vehicles power an electric motor by converting hydrogen to electricity. These vehicles can refuel in less than 10 minutes and perform on a single charge for more than 300 miles (483 kilometers).

Propane. This alternative fuel has been used in light-, medium-, and heavy-duty vehicles for decades. Consumers can either purchase propane vehicles from the manufacturer or convert an existing automobile. The fueling process is like pumping traditional gasoline, but there are currently fewer stations than EV stations. The market for propane vehicles is fragmented, with stronger markets in select States.

Natural gas. Natural gas is stored onboard a vehicle as compressed natural gas or liquefied natural gas. Compressed natural gas fuel systems transfer natural gas from the tank to the engine while reducing the fuel pressure. Liquefied natural gas fuel systems convert the liquefied fuel into gas before it is injected into the engine.

EV chargingtur4tur5lpg charginglng charging


Roadside signage indicates to drivers which types of fueling stations are available in the corridor. Source: FHWA.


The departments of transportation in Minnesota and South Carolina already have installed highway signage. The nascent Minnesota corridor located along I–94 has a handful of signs alerting motorists of the availability of alternative fueling stations. According to Timothy Sexton, construction and operations section director with the Minnesota DOT, the atmosphere at the DOT and among industry partners in the State has been enthusiastic. “It was actually pretty straightforward, [and] everyone was on board with the concept,” Sexton says.

Other FHWA goals for alternative fuel corridors include consistency and convenience, reliability and performance, and enhanced coordination among and between the public and private sectors. Here’s a closer look at what each of these goals entails.


Alternative fueling types have unique infrastructure needs, as indicated by the diversity of nozzles shown here.
Source: DOE Alternative Fuels Data Center,


Consistency and convenience. As it currently exists, the landscape of alternative fueling stations lacks a uniform geographic layout. Without consistency, consumers have little reason to trust that their vehicles will not run out of fuel before they could reach the next fueling station. The USDOT Alternative Fuel Corridor designations will ensure that drivers have access to alternative fuel facilities at consistent intervals across the Nation’s highways. Designations are based on the criteria developed by FHWA related to the distance between facilities for each fuel type.

Reliability and performance. FHWA aims to ensure that travelers can navigate between destinations quickly and safely. Research shows that consumers place a high premium on the peace of mind that comes with reliable fueling stations, like those offered to gasoline and diesel powered vehicles.

Enhanced coordination of public and private sectors. For any fuel corridor to maintain consistency, agencies at the Federal, State, and local levels have to work together to continue a dialogue about the share of public and private sector investment in the infrastructure.


Designated EV Alternative Fuel Corridors

FHWA designated Alternative Fuel Corridors across the country for EVs. Several also exist in Hawaii (not shown here). Green routes indicate corridors designated as “signage ready”. Orange routes indicate “signage pending” corridors. The difference between “signage-ready” and “signage-pending” designations is the maximum distance between fueling Source: FHWA.


Locations of EV Charging Stations

More than 16,000 EV charging stations exist nationwide, a higher number than for any other alternative fuel. Source: DOE Alternative Fuels Data Center,


FHWA has designated portions of 55 corridors across 35 States, covering approximately 85,000 miles (136,794 kilometers) of the National Highway System, as the backbone of a national network of alternative fuel corridors. A nomination process in 2016 resulted in these designations, which led to collaboration among FHWA, USDOT’s Volpe National Transportation Systems Center, the U.S. Department of Energy (DOE), and DOE’s National Renewable Energy Laboratory. Together, the agencies mapped all public EV charging, hydrogen, propane, and compressed natural gas (CNG) and liquified natural gas (LNG) stations located within 5 miles (8 kilometers) of the nominated corridors found on the National Highway System.

Other considerations for the alternative fuel corridors include the particular fueling methods employed. For the initial round of corridor designations, FHWA included both direct current fast charging (DCFC) facilities as well as Level 2 (240-volt charging) facilities. However, the second round request for designations only included DCFC, which allows for quicker charging than Level 2 facilities and charges at about 60 to 80 miles (96 to 129 kilometers) of range in 20 minutes. DOE is also considering the development of “extreme” fast charging, which can provide 200 miles (322 kilometers) of range in a little more than 15 minutes. As technologies improve, FHWA will revisit the parameters of new corridors to ensure they are meeting the most current needs of alternative fuel users.

Industry Partnerships Pave the Way

FHWA will have some help in meeting these goals. In addition to collaboration with DOE, State DOTs, and local agencies, FHWA is coordinating with industry stakeholders, hosting webinars in which numerous parties provide input, and attending industry events.

Industry participation is a necessity—after all, a highway is only as good as the vehicles that drive on it. As consumer interest in alternative fuels has grown, industry has responded. Automakers report that 11 percent of motor vehicle jobs in 2016 focused on alternative fuel and advanced technology vehicles. In addition, several industry stakeholders have expressed interest in adapting innovative power transfer technologies, such as recharging chips embedded in pavements to transfer power to vehicles, to U.S. highway design specifications.

Automobile manufacturers have continued to set ambitious goals to champion alternative fuel vehicles, such as Volvo’s high-profile plan to produce only hybrid and electric-powered cars by 2019. But it is not just passenger vehicles fueling the industry. Although medium and heavy trucks make up only 4 percent of vehicles on the road, they account for about a quarter of U.S. fuel consumption, meaning commercial and freight needs are driving an important sector of potential new growth for alternative fuels.

Manufacturers’ desire to produce for a growing market may be unsurprising, but what is more encouraging for the future of alternative fuel infrastructure is the enthusiasm stakeholders across the industry have in collaborating across public and private lines.

Fun Facts:
Putting Alternative Fuels on the Map
  • The United States is home to nearly 24,000 alternative fuel stations. Compare that to approximately 156,000 public retail gasoline stations.
  • A 2016 public opinion poll by the National Renewable Energy Laboratory shows EVs are top-of-mind when it comes to alternative fuels: 43 percent of respondents said it was the best option to replace traditional fueling vehicles for personal use. Respondents chose natural gas as their second choice at 24 percent.
  • Alternative fuels are growing internationally. The United Kingdom, France, and India are among countries with plans to transition to selling only alternative fuel vehicles by 2050, while China recently announced a plan to set its own target.


The idea of a cooperative network for alternative fuel vehicles is not an entirely new one. DOE’s Technology Integration Program has fostered such connections in the industry for more than 20 years, building innovative partnerships and coalitions across the country to reduce U.S. reliance on petroleum. Currently, nearly 100 local Clean Cities coalitions span the country. A group may include local businesses, fuel providers, community organizations, and nonprofits, working together to educate their communities about alternative fuels, seed local market growth, and reach petroleum savings targets.


Clean Cities Coalitions

Clean Cities coalitions, plotted here around the country, bring together local businesses, fuel providers, vehicle fleets, State and local governments, and community organizations to cut petroleum usage in their communities. Source: DOE.


One accomplishment of the group, which should not be underestimated, is the knowledge sharing that accompanies 20 years of data surrounding alternative fuel infrastructure. The National Renewable Energy Laboratory collects a robust volume of data from across the country. For example, at certain EV stations, charging station networks make status reports on a nightly basis. For other fuels, industry partners make regular calls to stations to determine availability—all to ensure that the data and maps are as accurate and up to date as possible. DOE’s Alternative Fuel Data Center Web site ( uses these data to map thousands of stations across the country. In addition, the DOE Vehicle Technologies Office works to make data accessible to consumers through online information campaigns and a station finder app.

Taking Shape: The First Installations

In 2017, South Carolina became one of the first States to add signage to an existing corridor, along a stretch of I–26 outside Charleston. Several other corridors in the State also have been designated as ready for signage. The Palmetto Clean Fuels coalition, with stakeholders as diverse as Piedmont Natural Gas, Nissan, Plug in Carolina, and the American Lung Association, estimates that South Carolina achieves an annual savings equivalent to more than 3.7 million gasoline gallons (14 million liters) in petroleum savings. Within State lines, the coalition counts more than 600 alternative fuel charging stations.

“This sort of local data about charging stations and alternative fuel benefits is crucial for public awareness and buy-in to new technology,” says Linda Bluestein, co-director of National Clean Cities. “It is also what has enabled FHWA’s corridor program to ‘connect the dots’ on alternative fuel infrastructure. Clean Cities coalitions collect data on thousands of charging stations from their stakeholders around the country. Without that kind of local knowledge, it wouldn’t have been possible to identify the FHWA corridors.”

The Upper Midwest, home to the first corridor signage along I–94, proves that these relationship models are built to last when it comes to alternative fuel corridors. The I–94 corridor spans over 1,500 miles across five States (Illinois, Indiana, Michigan, Minnesota, and Wisconsin) in a path called the “Great Lakes Zero Emission Corridor.” The five State DOTs, the city of Detroit, FHWA, and DOE joined with nongovernmental forces, including nonprofit and industry coalitions, such as the Drive Electric Minnesota advocacy group.

Officials overseeing the project hope that the partnership efforts in Minnesota can serve as a kind of incubator for the early stages of creating alternative fuel corridor infrastructure. “It takes a village to build a program like this,” says Wendy Dafoe, senior project manager at the National Renewable Energy Laboratory.

Connecting the Dots

Although alternative fuel corridors are still a new concept, the marketplace has experienced rapid growth—with no signs of stopping. Dozens of corridors await additional fueling stations in order to qualify as ready for signage. The corridors themselves are a tool to add more fueling stations around the country, strengthening a growing industry, and ensuring that this sector of the transportation market will have a strong future.

“It used to be, these charging stations were scattered dots on a map,” says Dafoe. “Now we see more cohesive clusters and corridors coming together. The industry has really grown up, and it’s an exciting moment to see the public and private sectors being smarter about working together to take the next step to build out these corridors.”

FHWA has put in place a series of goals to continue this work, including identifying barriers to installing more fueling facilities, locating sources of funding, promoting strong regional and national collaboration, and increasing cooperation with DOE’s Technology Integration Program and the National Renewable Energy Laboratory.

Current alternative fuel vehicle owners and prospective owners may not know what to expect once on the road, but the landscape is changing. Stakeholders in nonprofits, private industry, State and local transportation agencies, DOE, and FHWA are developing a robust infrastructure for these vehicles. Over the coming months and years, State DOTs are expected to expand sign installations along corridors throughout the country.


Photo: SCDOT.

South Carolina installed its first signage in summer 2017, following Minnesota to become the second labeled corridor.


“[Alternative fuel] corridors support regional cooperation in strengthening the use of alternative fuels around the country, and FHWA looks forward to working with our local and national partners to develop them further,” says FHWA’s Shepherd.

The ultimate goal is to make sure that the driving public is aware of where alternative fuel facilities are located on the Nation’s highways so there will be no more of an uncertainty than with a traditional gasoline vehicle. This innovative approach to a new marketplace will give a larger platform to alternative fuel technology, reducing the Nation’s petroleum use and dependence on foreign oil, and strengthening U.S. transportation infrastructure for the 21st century.

Diane Turchetta is a transportation specialist in FHWA’s Office of Natural Environment, primarily working on transportation and sustainability issues. Turchetta has been with FHWA for over 17 years in various positions working on a variety of transportation-related air quality matters including energy use, alternative fuels, and freight emissions. She holds a bachelor’s degree in public administration from Pennsylvania State University and a master’s degree in public administration from Virginia Polytechnic Institute and State University. Before joining USDOT, she worked at the U.S. Environmental Protection Agency on fuel-related issues.

Carter Purcell is a communications professional with experience across a range of environmental issues in transportation, energy efficiency, and agriculture. She works for the Cadmus Group, supporting marketing for FHWA’s Office of Planning, Environment, and Realty. She has a bachelor’s degree in English from Columbia University.

Sean Nyhan is a strategic communications specialist who works closely with transportation partners like USDOT, FHWA, and the Association of Clinical Research Professionals through his position at the Cadmus Group. He is a former reporter who covered environmental issues in New Jersey. Nyhan has a master’s degree in strategic communication from George Mason University.

For more information, see and, or contact Diane Turchetta at 202–493–0158 or