Electric road
An electric road, eroad, e-roadway, or electric road system is a road which supplies electric power to vehicles travelling on it. Common implementations are overhead power lines above the road, ground-level power supply through conductive rails, and dynamic wireless power transfer through resonant inductive coils or inductive cables embedded in the road.
Overhead power lines are limited to commercial vehicles while ground-level rails and inductive power transfer can be used by any vehicle, which allows for public charging through a system for power metering and billing. Research papers for the government of Sweden, published in 2019, and France, published in 2021, separately estimate that in-road conductive rail ERS is the most cost-effective.
there were about 10 operational ERS demonstrators around the world, and their business cases and deployment strategies are being evaluated. As of 2025 [|electric road technical standards] are only available for in-road rail of the three ERS technologies.
Government studies and trials have been conducted in several countries seeking a national electric road network:
- Korea was the first to implement an induction-based public electric road with a commercial bus line in 2013 after testing an experimental shuttle service in 2009. The first road and three subsequent electric road trials were shut down due to aging infrastructure amidst controversy over the continued public funding of the technology.
- United Kingdom municipal research projects in 2015 and 2021 found wireless electric roads financially unfeasible.
- Sweden started assessing various electric road technologies in 2013 under the Swedish Transport Administration electric road program. After receiving electric road construction offers in excess of the program's budget in 2023, Sweden pursued cost-reduction measures for either wireless or rail electric roads. The project's final report was published in 2024. It recommends against funding a national electric road network in Sweden as it would not be cost-effective, unless the technology was first adopted by its trading partners such as France and Germany.
- Germany published findings in 2023 on the wireless electric road system by Electreon. The system's receivers collect 64.3% of the power output of its transmitters, and it poses many difficulties during installation and blocks access to other infrastructure in the road. Germany trialed overhead lines in three projects in the 2010s and 2020s, and reported they are too expensive, difficult to maintain, and pose a safety risk.
- France found the same drawbacks for overhead lines as Germany, and began testing inductive and rail electric road systems in 2023. Testing of the inductive system is scheduled to conclude in September 2026.
- India announced plans in 2023 for a national electric road network, beginning with a road between Sohna and Jaipur. As of late 2024, ground-level power supply is being considered for the project.
Technology
, in a late 2010s overview of the subject, listed three power delivery types for dynamic charging, or charging while the vehicle is in motion: overhead power lines, ground level power through rails, and induction through rails or resonant coils. The TRL overview lists overhead power as the most technologically mature solution which provides the highest levels of power, but the technology is unsuitable for non-commercial vehicles. Ground-level power is suitable for all vehicles, with rail being a mature solution with high transfer of power and easily accessible and inspected elements. Inductive charging delivers the least power and requires more electrical roadside equipment than the alternatives.The electric road studies by the French government published in 2021 similarly found in-road rail as the most suitable and cost-effective solution. One of the studies ruled out overhead lines due to safety concerns, and another ruled out inductive charging as it didn't meet France's 250 kW minimum average power requirement.
Effects on roads
The German Ministry of Economy, BMWK, reported in 2024 that it found that overhead power lines pose safety risks for emergency services, and the lines' roadside poles pose a collision risk for motorists.A study published in 2017 found increased formation of reflective cracks for roads with in-road inductive coils. As part of the French government study of electric roads beginning in 2023, in-road inductive charging infrastructure was found to cause excessive strain for road surfaces using standard road materials. The study recommends using more robust materials, which reduced strains to a satisfactory level. The study found increased risk of thermal damage to the road due to the induction coils exceeding temperatures of. The 2023 tests showed risk of debonding between the inductive coils casing and the asphalt concrete. ÉTS and Université Laval studied the structural performance of in-pavement inductive coils in 2025, similarly finding evidence of debonding. INDOT has tested in 2024 a DWPT installation with special polymer-concrete previously used for bridges.
Standardization
Governments and research institutes in the early 2020s recommended standardizing ERS technologies before choosing one specific technology. A report by the Research Institutes of Sweden recommends inter-city infrastructure capable of 300 kW or more for best cost-effectiveness. The Swedish National Road and Transport Research Institute similarly recommends a system capable of delivering 300 kW per truck. The French Ministry of Ecology working group recommends 400 kW for 44-ton trucks driving at 90 kilometers per hour along a 2% grade, or at minimum 250 kW so the truck can charge along flat or gently-sloping roads. The European Commission published in 2021 a request for regulation and standardization of electric road systems.Ground-level rail electric roads
A standard for electrical equipment on board a vehicle powered by ground level rail electric road system, CENELEC Technical Standard 50717, has been approved and published in 2022. A complete ground-level power supply system standard, CENELEC technical standard 50740, was drafted in accordance with European Union directive 2023/1804. The standard has been approved and published in 2025.Wireless electric roads
Standards for inductive charging for vehicles have been available since 2020, though they are not immediately suited for electric roads. For instance, the CEO of IPT, a vehicle inductive power transfer company, regards the existing standards as "extremely expensive" for use in electric roads. Cost-effective implementations are being explored by IPT using its Primove inductive cables technology which it bought in 2021 from Bombardier. WiPowerOne and Electreon, two wireless electric road companies, have been working on new dynamic inductive charging standards since 2021. ENRX, which is composed of several companies including IPT, announced in November 2024 that it plans to collaborate with InductEV to standardize dynamic wireless power transfer. SAE International notes that wireless charging systems do not have well-established foreign object detection technologies, and proposes establishing safety tests for these technologies. Foreign objects pose a fire or burn risk if metals or organisms are between the ground pad and the receiver when the system is active. SAE International has started developing standards for dynamic wireless power transfer in 2023.Business model
A 2020 Swedish Transport Administration electric road program report anticipated that a national electric road network would require interfaces between several players: the electricity supplier, the power grid company, the vehicle manufacturer, the road owner, the electric road technology operator, the metering and billing provider, and the user of the electric road. The ownership model can vary: the power grid company may own the secondary roadside electrical substations that power the electric road infrastructure or they may be owned by other players, and the power reading and payment system may be owned by a player separate from the infrastructure operator.A 2026 review of electric road systems by participants in the ERS trials for the French government reported that ERS operators could promote ERS usage with its low cost to users. Operators can purchase energy at around €0.09/kWh and sell it to ERS users at around €0.19/kWh, a lower cost than the average rate for home charging in France. At these rates, the gross profit margin would be over 50%. Return on investment would be 4% annually over 32 years due to upfront costs of infrastructure, and maintenance and operating costs. Contemporary toll roads in France charge significantly more per kilometer driven than what ERS charging per kilometer would cost at 50% gross margin, allowing toll road operators to implement ERS, which would, along with the lower electricity cost, incentivize toll road users to install ERS chargers on their vehicles. Energy savings increase with the weight of the vehicle; large diesel truck operators that would switch to battery-electric ERS trucks would recoup over 93% of the toll road charge in fuel cost savings along the toll road. These factors financially allow the implementation of ERS through the French toll highway concession model. Countries without a concession model could use public–private partnerships for the same end.
Early implementations
Overhead power lines have been used for road transport since at least 1882 in Berlin with Werner von Siemens's trolley buses. Over 300 trolley bus systems were in operation in 2018. Power to trolley buses is normally delivered using a pair of trolley poles positioned on top of the vehicle which extends to the overhead power lines. Implementations for highway vehicles have been developed in the late 2000s and 2010s but they are not suitable for non-commercial vehicles such as passenger cars.Ground-level power supply in the form of electrified rails is similar to overhead power lines in implementation. Instead of an arm or pole extending to overhead power lines, a mechanical arm extends from the bottom of the vehicle and aligns with a rail embedded in the road. The rail is then powered, and power is transferred through the arm to the vehicle. Ground-level power supply is considered aesthetically preferable to overhead wires and it is suited for all types of vehicles.
The concept of a wireless ground-level power supply for vehicles was first patented in 1894. A static-charging system for shuttle buses was demonstrated in New Zealand in 1996 using inductive coils. Similar stationary charging systems for buses and other vehicles have been implemented by Conductix-Wampfler and Bombardier Primove. Primove was further enhanced to include dynamic charging while driving using inductive cables.
Development of electric road systems has matured significantly from the late 1990s through the 2010s. Several companies have developed and implemented electric road systems in the 2010s.