Wireless electric road system for propulsion and charging of electric vehicles in highways

Abstract

Wireless charging is a technology that is projected to promote the acceptance of Electric Vehicles (EV) due to its capability to reduce transport emissions, improve charging convenience and promote environmental sustainability. Technological advancement in dynamic wireless power transfer has contributed to the expansion of Electric Road Systems (ERS) that offer charging infrastructure for Electric Vehicles (EV). ERS is an emerging technology aimed at electrifying road transport by supplying EV with power enabling EV's with the possibility to charge while driving. ERS is an important technology to enhance the electrification of EV thereby addressing battery limitations and further decrease fossil fuel dependency. Although prior studies have evaluation the potential of ERS. There are fewer studies that extensively explored the applicability of wireless ERS in highways or long-distance corridors. Therefore, this article identifies factors as challenges that influences the deployment of wireless ERS and potential application of wireless ERS for sustainable transportation. More importantly this study investigates the feasibility of wireless ERS to decarbonize road vehicles in long-distance corridors. Key findings from this article assess the maturity level of different ERS technologies by presenting use cases and initiatives of ERS focusing on wireless power transfer subsystem and the development of ERS in highways.

Introduction

Cities and communities are experiencing a progressive development towards the electrification of road transport, particularly for passenger cars (Márquez-Fernández et al., 2019). This is because the transportation sector contributes to about 21% of global emissions of which road vehicles is responsible for more than half of the emission. This increase has resulted to the adoption of Electric Vehicles (EV) in long-distance corridors (Wendt et al., 2024). However, the current EV charging infrastructure is mostly based on plug-in charging stations, which limits the widespread adoption of EVs due to limitations such as inefficient battery range, availability of space needed to install charging infrastructure at a large scale (Wendt et al., 2024; Dávila-Sacoto et al., 2025). Another challenge impending the wider adoption of EVs is users’ perception that EVs cannot travel long distance (range anxiety), without requiring a recharge (Niestadt, 2019). This could possibly be due to inadequate charging infrastructure or limited awareness that charging infrastructure exists (Niestadt, 2019; Aybar-Mejía et al., 2025).

Additionally, the electrification of heavy vehicles is significantly more challenging, since most of these vehicles require large and heavy batteries to reach a particular driving distance resulting to decrease in payload and less feasible economic gain vehicle (Márquez-Fernández et al., 2019). Besides, the fast charging which is the leading solution for charging heavy vehicles leads to extreme battery degradation (Wendt et al., 2024). Due to these challenges an alternative solution termed “Electric Road System (ERS)” has been proposed for propulsion and charging of EVs battery while they drive along the road (Gustavsson and Lindgren, 2020; Wenander and Alaküla, 2024; Wendt et al., 2024). Thus, ERS enables dynamic power transfer from the road to an EV while the vehicle is in motion (Márquez-Fernández et al., 2019; Lindgren, 2020; Wenander and Alaküla, 2024; Banegas-Arias et al., 2026).

ERS is being implemented via different power transfer methods from the road to the vehicle, such as through overhead-line (e.g Siemens “eHighway), rail, and wireless solutions (via induction charging) (Karlsson et al., 2018; Sundström and Sundelin, 2018; Gustavsson and Lindgren, 2020). The overhead lines, much like a train or a trolley enables the vehicle to receive electric energy via a pantograph supporting the electrification of vehicles tall enough where aesthetics is not of significance (Karlsson et al., 2018). As several aspects need to be considered when determining where the ERS components should be implemented. ERS are based on inductive and conductive charging conditions (Karlsson et al., 2018). This research is more aligned to wireless ERS solutions which utilizes magnetic fields that provide energy needed to propel and charge the vehicle.

In wireless ERS energy can be supplied for both propulsion of the EV (thereby reducing the need for onboard energy storage), and for charging of the onboard battery (Sundström and Sundelin, 2018; Wenander and Alaküla, 2024). Although, a few ERS are technologically matured and are being deployed and demonstrated in Israel, Sweden, Germany, South Korea, etc. Existing ERS technologies are still a long way from establishing large-scale deployment (Gustavsson and Lindgren, 2020). This is due to challenges that impacts various stakeholders, such as road authorities, decision makers, and technology developers from deploying wireless ERS for sustainable transportation in highways. To this end this current study examines the following research questions.

What are the key components and sub-systems needed to deploy wireless ERS for sustainable transportation in long-distance corridors?

Which factors influence the deployment of wireless ERS for sustainable transportation in long-distance corridors?

Accordingly, this study contributes to the literature by exploring the usefulness of wireless ERS and further identifies the challenges and potential application of wireless ERS for sustainable transportation in long-distance corridors. Findings from this study will provide decision makers and potential investors with evidence needed foster the upscale commercialization of ERS operation in cities and communities. The remaining section of this paper comprises of the methodology in section 2. Section 3 is the findings and Section 4 is discussion and implications. Finally, section 5 is the conclusion.

Methodology

A qualitative literature review was adopted in this study to select suitable sources that provides secondary data needed to examine wireless electric road system for propulsion and charging of EV in highways. A qualitative literature review was employed as the appropriate approach as it support researchers to methodically synthesizes, extract, and interprets non-numerical data. This helps in investigating themes, concepts, and knowledge across different studies to deeply understanding a domain, rather than simply summarizing them. Qualitative literature typically employs an inductive method to identify developing patterns, that often results to newer theoretical models (Anthony Jnr, 2021).

Moreover, an inductive approach is based on a bottom-up method where data is first collected, then analysed and extracted to identify themes, patterns, and categories, which eventually contributes towards conceptualizing a concept or agenda from the ground up. Accordingly, the qualitative literature review was conducted using online data sources such as Scopus, Web of Science, and Google Scholar. As these sources provide a wide range of relevant papers and are easy to use (Anthony Jnr, 2020; Borin and Tjernlund, 2020). Overall, the qualitative literature review focuses to get a better idea of the existing research thereby helping in building a good foundation. In the context of this study understanding the complexity of the factors that influence the deployment of wireless ERS and recommendations that can be adopted by cities and communities for sustainable ERS transitioning.

Hence, this review was centred around literature related to key components needed to deploy wireless ERS, application of ERS, barriers towards adoption of ERS, technological and infrastructural dependency and business models. The secondary sources comprise of published articles in peer reviewed journals, conference proceedings, book chapters, theses, dissertations, technical reports and documentation related to ERS and sustainable transportation. These selected sources (as seen in the reference section of this paper), are utilized to deepen the researcher`s understanding in getting a better understanding of ERS landscape. As well as the technological, economic, social, legal, political, and institutional perspectives about the potential of ERS towards sustainable electrification of road transport sector.

Findings

Overview of electric road systems in highways

Road transportation is one of the major contributors to CO₂ emissions, thus there has been a need to decarbonize this sector. While there has been a progressive shift towards EV adoption across road passenger transportation (Čičić and Delle Monache, 2024). As such over the years there has been increase sales of electric road vehicles global (Niestadt, 2019). This is largely influenced by the mass adoption of EV in long-distance corridors (Anthony Jnr, 2021). The availability and accessibility of charging infrastructure for personal EVs enabling long-distance travel with little interruption pose additional challenges (Anthony Jnr, 2021; Bokolo, 2025).

This are necessitated the need for seamless charging such as ERS which has emerged as one of the possible alternatives for promoting sustainable transportation in highways, particularly for heavy vehicles Since 2010 (Tongur and Sundelin, 2016). ERS offers an innovative technology that could contribute to reduce battery capacity of EVs, extend driving range, and lessen the societal cost of electrification (Karlsson et al., 2018; Jacob et al., 2023). ERS is defined as dynamic power transfer from the road infrastructure to EV while the vehicle is in motion and can be achieved through the installation of electrical equipment operating beneath the vehicles (via inductive wireless solutions and/or conductive power transfer as in rail) or above the EV (i.e., mostly via conductive overhead lines) (Tongur and Sundelin, 2016; Lindgren, 2020). ERS aims to address limitations faced with the batteries used for EVs such as the driving range limitation, high cost, and the fact that existing EV battery make the vehicle to be heavy especially for long range vehicles (Taljegård et al., 2017).

ERS possess the potential to minimize greenhouse gas emissions, decrease air pollution as well as decrease noise in highways, while promoting energy efficiency across the road transport sector (Sundelin et al., 2016; Gustavsson and Lindgren, 2020). Likewise, ERS can heavily contribute to reduce fossil fuel dependency across the transport system towards decarbonating the entire road transport solutions (Sundström and Sundelin, 2018). Additionally, the application of ERS offers the possibility to reduce use of large batteries mainly in heavy vehicles (Taljegård et al., 2017). Thus, ERS makes it possible to decrease the installed battery capacity thereby resulting in a decrease of the weight and overall cost of the vehicle (Karlsson et al., 2018). Thus, the deployment of ERS can contribute to decrease the size of the battery while ensuring that the usability of the EV remains unchanged (Márquez-Fernández et al., 2019).

However, the deployment of ERS for the electrification of road vehicles is challenging from several viewpoints (Wenander and Alaküla, 2024). These aspects comprise of grid power availability, traffic volume, power needed by the EVs, and total energy use, etc. (Karlsson and Alaküla, 2022). Another issue is the effect that the widespread deployment of ERS may have on the community energy grid, through total energy demand (Čičić and Delle Monache, 2024). Irrespective of the capabilities of ERS, prior research on ERS has mostly focused on technological and economical aspects (Čičić and Delle Monache, 2024). The social aspect has not been well addressed in the literature.

State-of-the-Art of conductive charging in ERS

Conductive charging provides a promising solution for the electrification of road transportation, mainly for heavy vehicles and long-distance journey but also for light vehicles such as passenger EVs (Márquez-Fernández et al., 2019). Conductive charging a physical connection is established that enables direct flow of electric current from the road and the vehicle. Evidence from the literature maintained that in pilot test sites conductive ERS can be constructed at a significant lower cost as compared to other competing alternatives (Márquez-Fernández et al., 2019). The conductive connection is mostly preferred for ERS as it requires a less complicated and relatively easy design to be built and supports high power transfer levels (hundreds of kW) (Karlsson et al., 2018). The dynamic transfer of electric power in conductive charging can be carried out from the road as “ground conductivity” or through overhead transmissions lines as “overhead conductivity” via pantograph (Taljegård et al., 2017).

In the overhead conductivity electric power is transmitted and returns to the vehicle in catenaries suspended above the road via pylons. The vehicles capture the electric power using installed pantographs on the roof (Jacob et al., 2023). Overall, the “overhead lines” are mostly used by heavy vehicles (such as buses and trucks) whereas the “electrified rail in the road” can be utilized by all type of vehicles (such as cars, buses, and trucks) (Taljegård et al., 2017).

Conversely, for ground conductivity, electric power is delivered and returns in linear structures or “rails” installed on the roadside or within the roadway. This provides electrical connection to the EV via retractable pins or pads located underneath the road (Jacob et al., 2023). Thus, in ground conductivity, electric power supply is supplied via a physical pick-up that connects to an electrified rail in the road (Taljegård et al., 2017).

Moreover, conductive ERS either deployed under the vehicle or on the side of the road can be utilized by both light and heavy vehicles, amounting to a much lower cost which is also beneficial to the society (Márquez-Fernández et al., 2019). However, the conductive connection produces friction and wear, which can produce Noise, Vibration, and Harshness (NVH) issues arising from various aerodynamic, mechanical, and electrical sources within the EV, significantly disturbing users’ comfort and perceived quality. Also, conductive charging does not offer galvanic isolation and the pick-up needs to be able to compensate for possible misalignment between the EV and the ERS charging tracks (Karlsson et al., 2018). However, due to the potentials of conductive charging, there are significant research efforts being dedicated towards the deployment of conductive ERS systems (Márquez-Fernández et al., 2019).

Applicability of inductive charging in ERS

In the inductive charging electric current in power lines or primary coil are situated on the roadway ground, creates magnetic fields where a pick-up coil or secondary coil is installed beneath the vehicle to receive power transmitted to the EV (Taljegård et al., 2017; Karlsson et al., 2018; Gustavsson and Lindgren, 2020). Thus, in inductive charging power is transferred through coupled magnetic field, capacitive, utilizing coupled electric field. In this study inductive charging is also referred to as wireless charging or cordless charging. The concept of wireless ERS is resonant with Wireless Power Transfer (WPT), which was first demonstrated by Nikola Tesla in the 1890s (Wendt et al., 2024). Technically a WPT is an infrastructure that transmits electric power via the vacuum of space without utilizing wires (Ceravolo et al., 2016). Inductive charging employs Inductive Power Transfer (IPT) technology supported by near-field WPT technology that enable cordless charging solution of EV in ERS. Hence WPT enables a contactless transfer of electric power between transmitter coils positioned under the roadway and receiver coils installed on board the EV, through the magnetic field created between the coils (Jacob et al., 2023).

WPT enables dynamic wireless charging in recharging EVs while the vehicles are moving without the need to stop (Ceravolo et al., 2016). Inductive charging can be integrated to ERS enabling energy to be transferred to the vehicle via wireless technology (executed as WPT) while in motion. The energy can be utilized not only to propel the vehicle but also to charge the battery so that it can be utilized at a later stage (Márquez-Fernández et al., 2019). Inductive charging has the advantages that it is just wireless, no physical contact is required thereby eliminating wear. It provides galvanic isolation due to its nature (Karlsson et al., 2018). The application of WPT as wireless ERS in long-distance corridors for shared charging not only decreases the overall cost of EV ownership and environmental impacts but also offers the advantage of unlimited or extended range by minimizing the need for large batteries (Wendt et al., 2024).

In long-distance corridors wireless ERS can be applied to different type of vehicles (such as cars, buses, and trucks) (Taljegård et al., 2017). However, researchers such as Ceravolo et al. (2016) argued that the infrastructure needed to build wireless ERS in highways could be expensive to implement. Also, the deployment of wireless ERS requires more components to be installed on board the vehicle and, if higher power levels are required, the secondary coil on board the EV will ned to be substantially increased in size (Karlsson et al., 2018). Although inductive power transfer from the road to EV in motion have been explored in prior research in public roads (Sundelin et al., 2016). Similarly, a few certain patents exist that have proposed different approaches that integrate WPT with existing road infrastructure (Ceravolo et al., 2016). Nevertheless, existing ERS infrastructures are still not scalable enough for commercial deployment (Sundelin et al., 2016), even though the solutions are deemed suitable for real applications, there are very limited numbers of real-world deployment of wireless ERS in long-distance corridors (Ceravolo et al., 2016).

Operationalization of wireless ERS in highways

Wireless ERS can supply electric power to the EV acting as either a variable/AC source or an unregulated DC voltage source. The “unregulated DC voltage source” case, no rectifier is required, and the pick-ups can be immediately linked to the isolated DC–DC converter, transmitting electric power to the “High-Voltage (HV) traction” battery (Márquez-Fernández et al., 2019). Where the “high-voltage traction” denotes high voltage (usually 400 V to 800V+), electrical system in EV that powers the motor to propel the wheels of the vehicle. The high-voltage traction comprises of the motor, HV battery, and inverter optimized for high-power output, fast charging, and energy efficiency often utilizing silicon carbide (SiC) technology. The main components of high-voltage traction systems for an EV are shown in Figure 1.

Figure 1.

Main components of high-voltage traction systems in EVs.

Evidence from the literature (Márquez-Fernández et al., 2019), mentioned that the ERS with a DC supply (unregulated DC voltage source) solution has been implemented by the eHighway-electrification of road freight transport by or the Aesthetic Power Supply (APS) Service-proven catenary-free tramway operations by Alstom. Furthermore, findings from the literature (Sundelin et al., 2016) mentioned the operationalization of wireless ERS comprises of different sub-systems such as road operations, electric power transfer, road network, battery energy storage, electric vehicle and the control unit as seen in Figure 2.

Figure 2.

Sub-systems for the operationalization of wireless ERS.

Among these sub-systems “road operation” is important for the orchestration of ERS. This is because it is responsible for energy management of the overall ERS, manages EV users’ information and further handles billing and payment. Road operation also controls access and lane control of the road employing vehicle identification. Another important sub-system is the “electric power transfer” which is defined into three key components (Sundelin et al., 2016), which comprises of road power transfer, vehicle power transfer and control as seen in Figure 3. Once an EV enters the ERS segment of the road, then the vehicle is detected by ERS. A sensor installed on the vehicle detects electric power supplier (Gustavsson and Lindgren, 2020). To enable communication for electric power transfer from the ERS electric equipment and the EV, wireless ERS typically deploy two types of communication protocols which comprises of low-level communication and high-level communication.

Figure 3.

Schematic view of the electric power transfer components adapted from (Sundelin et al., 2016).

First, the low-level communication as specified in IEC 61980 (which is an international standard deployed for wireless power transfer in EV), handles basic electric power transfer for instance coil activation and shutdown. Then, the high-level communication defined in ISO/IEC 15118 aligned with IEC 61980 standards provides a set of communication features required to support the transfer of wireless electric power (Wendt et al., 2024). Analogous to conductive charging, each wireless charging session will be authenticated after which the electric power transaction is authorized before commencing the main electric power transfer. During the electric power transfer, electricity demand and metering data regarding the received energy is being consumed. In the case of possible failures, the high-level communication provides additional data on the cause and description of the fault. Afterwards, the communication session finishes (Wendt et al., 2024).

The deployment of wireless ERS has been supported by IoT devices such as the weigh-in-motion (WIM) system deployed for axle detection of the vehicle, deployed to support transportation safety, traffic monitoring and weight enforcement, pavement management, and up-to-date pavement design protocols (Ceravolo et al., 2017). The pick-up controls manage EV movement and position of the electric power receiver device. In the case of normal operation, the electric power is switched on, but in case of emergency or failure detection the electric power will be switched off as a safety measure (Gustavsson and Lindgren, 2020). When the energy receiver of the EV is successfully connected to the ERS electric power supplier, the current control of the electric power transfer is handed over to the EV through fuses and overvoltage protection. The energy metering device and ERS performance is monitored in a remote operation and control centre (Gustavsson and Lindgren, 2020). For effective electric power control, the ERS road component handles the detection of the EV as well as the transfer of power from the road component to the EV. The pick-up control of the EV manages electric power transfer ensuring safe activation and operation measures needed for successful transferring of electric power after response from the EV. The infrastructure control component monitors the energy handover and energy system operations (Sundelin et al., 2016).

The “road network” subsystem comprises of the different components such as the pavement, auxiliary and barriers. The pavement comprises of the actual structural body of the road and the road markings. Whereas the auxiliary elements include road signs and other mandatory components linked to the outside of the road bank. Then, the barriers elements encompasses both safety and sound. Then the “battery energy storage” subsystem as seen in Figure 2 comprise of the components required for distribution, transmission, and management of energy to the “electric vehicle” subsystem. The distribution module involves how electric power flows through the district grid to the power transfer subsystem. The transmission module entails how the electric power flows from the generation source (e.g via renewable energy source), via the national grid to the ERS. The management module controls the operation and balancing of the energy used by the EV (Sundelin et al., 2016; Jnr, 2025).

The “electric vehicle” subsystem comprises of the components needed to convert the electric power from the power transfer subsystem (AC or DC), into either propulsion of the EV, charging and storage of energy. Lastly, the “control unit” provides EV user information on the state of the ERS, vehicle positioning, EV battery state, and fleet management for other EVs using the ERS (Sundelin et al., 2016; Bokolo, 2025). Furthermore, the operationalization of wireless ERS within long-distance corridors involves stakeholders mostly from different fields (Damousis et al., 2014; Wang et al., 2019). Evidence from the literature indicated key stakeholders as shown in Figure 4.

Figure 4.

Stakeholders involved in wireless ERS within highways.

Figure 4 depicts the key stakeholders involved in the operationalization of wireless ERS within highways. Where the first stakeholders are involved in the development and implementation of ERS technology which are checked for compliance based on existing policies and legislations that govern the operation of ERS technology. The final group stakeholders involve the authorities, operators and end users of ERS technology.

Use cases and initiatives of electric road system

Rail-based ERS solutions

A rail based ERS solution uses a conductive equipment installed within the road to provide energy needed for the vehicle. In this use case electric power is transferred to the EV via a robotic arm mounted beneath the EV, which follows the rail. The rail based ERS technology has been built by three suppliers and experimented at two test tracks in Sweden. The company “Elways AB” (https://evias.com) has tested rail based ERS in a 350 m test track outskirt Arlanda in Sweden. In the second phase of the project scheduled for 2017, the rail based ERS solution is planned to be experimented on a 2 km public road with the rail based ERS solution entirely integrated on a DAF truck utilizing E-Traction and a ZF powertrain (Sundelin et al., 2016). Similarly, Alstom has carried out testing jointly with AB Volvo along a 400 m test track at the Volvo test site in Hallered, Sweden. The vehicle integration is being carried out as part of the “slide-in research project” (Olsson, 2013). Another project was carried out by Elonroad AB (https://elonroad.com) which is aimed at installing the rail on the surface of the road as a substitute of embedding it within the road in comparison to rail based ERS solution work carried out by Elways and Alstom (Sundelin et al., 2016).

Overhead-line ERS solutions

The overhead-line ERS solution deploys an overhead line that provides energy to the vehicle. The overhead-line are positioned above the vehicle enabling the transfer of energy to the vehicle via a robotic arm that follows the overhead line installed on top of the vehicle (Sundelin et al., 2016). A use case of the overhead-line based ERS solution has been tested on the Siemens 2 km test track in Berlin, Germany. The full vehicle integration has been operated jointly with Scania and test for a Mack truck is in progress. Within 2016, the overhead-line ERS solution was tested on public roads in the USA and Sweden. The US test was carried out on a 1-mile urban road in Carson within the vicinity of Los Angeles, whereas the Swedish test was carried out on a 2 km stretch of the E16 highway in the outskirt of Gavle (Sundelin et al., 2016). Moreover, other countries such as Germany have called for demonstration of overhead-line ERS solutions (Sundelin et al., 2016).

Wireless ERS solutions

The wireless ERS solution is the focus of this study deploy magnetic field to provide energy needed to propel and charge the EV. The electric current within the primary coil built in the road generates a magnetic field, which induces a current within a secondary coil mounted beneath the EV (Sundelin et al., 2016). A few wireless ERS test have been demonstrated one of which is the test carried out by On-Line Electric Vehicle (OLEV), which is a spin-off from the university KAIST in South Korea, since 2008 experimenting inductive electric power transfer. The OLEV solution was tested on a public road within KAIST's Daejeon campus ever since 2012. Similarly in 2013, a bus route has been carried out in Gumi, South Korea with a total of 144 m of installed induction coils enabling traversed two buses. Likewise, the Endesa EU project in 2016, deployed an electric bus route in Malaga, Spain via inductive power transfer implemented by CIRCE (https://fcirce.es/en/project/unplugged). Where eight 80 cm based on 50 kW coils was fitted along 100 m of the bus route.

Furthermore, the “FABRIC” an EU funded project demonstrated dynamic inductive power transfer across two test tracks in 2016. Inductive solution implemented by SAET group was tested on a test track using a Fiat van outside Torino, Italy (https://cordis.europa.eu/project/id/605405). As part of the FABRIC project a second demonstration was carried out in the Vedecom test track in Satory, France, where power transfer solution was based on the commercially available static solution from Qualcomm integrated on a Renault van. Another EU project termed “UNPLUGGED” investigated how the use of inductive charging of EV in long-distance corridors can enhances the sustainability and convenience of car-based mobility (https://cordis.europa.eu/project/id/314126/).

Another study is the ELinGO project (www.elingo.no), carried out a concept analysis for the electrification of road freight transport by investigating relevant technologies, organization, business models, and environmental consequences. The ELinGO project further explored different ERS technology suitable for the E39 coast road (Sundelin et al., 2016). Moreover, the Swedish Transport Administration have been involved in a few ERS demonstration test site such as the overhead lines in Sandviken, inductive system in Visby, road-bound electric rail in Arlanda, and the road-bound electric rail in Lund (Lindgren, 2020). Additionally, commercial entities such as Bombardier are conducting research into dynamic inductive power transfer as part of their Primove commercial static solution (https://sustainable-bus.com/news/ipt-group-primove-wireless-charging). The system has been incorporated into a Scania truck and tested across an 80 m closed test track in Mannheim, Germany, as part of the Slide-in project (Sundelin et al., 2016).

In the United Kingdom (UK) the Transport Research Laboratory has carried out a viability study of dynamic inductive power transfer across the England's major roads network on behalf of the Highways England for solutions on test tracks. In 2016 the Utah state university in the US carried out a dynamic inductive power transfer for test track deploying an inductive charging system with a range from 25 kW to 40 kW tested utilizing a 20-passenger bus. Also, the ELINA project (https://ffe.de/en/projects/elina-deployment-of-dynamic-inductive-charging-infrastructure-in-public-transport/), which aimed at deploying dynamic inductive charging infrastructure in public transportation. With the support of the German government the project provided wireless charging infrastructure in the City of Balingen. The project provided two bus stops with one kilometer of wireless ERS charging systems demonstrating a 12 m city bus operated since May 2023 (Wendt et al., 2024).

Factors influencing deployment of wireless ERS

Evidence from the literature reveal that the application of ERS can contribute to decarbonizing road transport (Plötz et al., 2024), but the widespread deployment of this technology is still under development due to technical, economic, social, and institutional factors that needs to be addressed. Therefore, this section aims to identify factors that influence the deployment of wireless ERS for sustainable transportation in highways as seen in Figure 5.

Figure 5.

Factors that influence the deployment of wireless ERS.

Figure 5 illustrates the factors that influence the deployment of wireless ERS for sustainable transportation in highways. As shown in Figure 5 one of the key factors mentioned in the literature is the lack of interoperability and standardisation as several there are different versions of ERS being operated today which are based on different technical specifications. For example, the technology that enables interaction between pantograph and overhead lines supporting the electrification of heavy trucks as well as for current collectors for ground-level feeding system operated both in the European Union and in other regions of the world are based on similar but different standards (Plötz et al., 2024). Similarly, despite the promising benefits of wireless ERS as a contributor for charging EV there is a need to establish common regulations internationally , ensuring the deployment of compatible systems that facilitate cross-border wireless charging and propulsion (Wenander and Alaküla, 2024; Anthony, 2026).

Thus, there is a need for changes in transport policies and regulations that contributes towards the spread of ERS technology (Lindgren, 2020). The deployment of wireless ERS is influence by the existing environmental and climate effect on the ERS equipment (Lindgren, 2020). Thus, there is a need to encapsulate the electrical components such as the resonant circuit via a potting system that protect against thermal, mechanical, and chemical stresses (Wendt et al., 2024). For instance, the winter conditions in regions such as in Norway, Sweden, Finland and other part of the world experience heavy snowfall and other weather conditions that can weaken sensors and other electrical equipment (Lindgren, 2020). Initially, during the winter season in Sweden the pantograph operational equipment experienced difficulties in properly detecting the overhead lines. Due to the accumulation of snow on the horizontal support beams for the contact wire. These accumulated snows then fall on vehicles using the road, which may result in a potential safety risk for overhead ERS line systems (Lindgren, 2020).

Additionally, the deployment of wireless ERS is influenced by external environmental factors such as the traffic intensity, speed profiles of vehicles, and state of the road (Sundström and Sundelin, 2018). The state of the road is based on the number of vehicles or axles, vehicle load, vehicles trajectory, road elevation or slope of the road, acceleration in the pavement, vertical stress, horizontal strain, temperature, humidity which influences the condition of the road surface (Sundström and Sundelin, 2018). Furthermore, there is a need for additional and timely maintenance activity to clear the snow and ice that enters inside the rail. The electric rail equipment can be equipped with heating cables that helps to melt the snow and ice. This can also be supported using special purpose de-icing maintenance vehicles. Another challenge is the sensitivity to salt used for winter road maintenance (Lindgren, 2020). As salt is used to prevent ice formation on the road (Márquez-Fernández et al., 2019). The joints and gaps between the road segments allow for the penetration of saline solution which result in decreased impedance in the electrical equipment (Lindgren, 2020).

Also, findings from Márquez-Fernández et al. (2019) indicated that the accumulation of salt effectively decreased the insulation resistance between the different electrical equipment, resulting to a higher AC voltage in the pick-ups and sub-frame which are coupled to the chassis of the vehicle. The installation and implementation of wireless ERS solution up-front involve extensive investments including road network and electricity grid components implying a significant development of the transport systems, e.g., concerning how EV are designed and utilized (Taljegård et al., 2017; Sundelin et al., 2018; Sundström and Sundelin, 2018; Gustavsson and Lindgren, 2020). Similarly, it is comparatively challenging to reach breakeven for ERS in comparison to petrol and diesel road systems (Sundelin et al., 2018). Furthermore, there is a challenge concerning financing and possible business models needed to be adopted during the deployment and operation of wireless ERS (Wenander and Alaküla, 2024). Although wireless ERS are economical feasible, there is an issue related to the billing and metering needed to enable public use of ERS infrastructure. Thus, the ERS operator must be able install metering and billing services based on the transferred energy consumed by EV (Wendt et al., 2024). As such it is still unclear, whether the financing of ERS in long-distance corridors should be undertaken mainly by the private vehicle owners, businesses or the government (Wenander and Alaküla, 2024; Bokolo, 2026).

Thus, the availability of investment and operational costs needed for the deployment of per kilometre and direction of ERS ranges between EUR 1.1 to 1.65 million. In addition, about 2% of invest are projected as operational costs annually. As such there has been discussion for the uptake of the state to participate in part ownership for the road or involvement of private and/or public partnerships in the construction of ERS (Plötz et al., 2024). Also, there is a need for regular operational maintenance needed for proper functioning of the wireless ERS infrastructure which has prompted additional costs (Wenander and Alaküla, 2024). Furthermore, the deployment of wireless electric road system will result to grid congestion thereby increasing the net electricity demand caused by dynamic power demand of multiple EVs simultaneously recharging via the electrified road. Thus, there is need to setup contingencies to manage the amount of electric power (how much), if it correlates with peaks in energy use (when), and how the new load (ERS) will be geographically allocated (where) as the use of ERS increases (Taljegård, 2019). Thus, concerns regarding the integration to the electric grid system are needed to be considered in setting up an ERS (Sundström and Sundelin, 2018).

In relation to direct and indirect costs and tax considering the current funding or exemptions provided by the government for operation of the state transport infrastructure (Lindgren, 2020). Accordingly, findings from the literature (Sundelin et al., 2018), reveal several costs incurred that needs to be addressed in achieving wireless ERS such as road costs, grid costs, vehicle costs, energy costs, and possibly road tax and insurance as seen in Figure 6.

Figure 6.

Cost involved in setting up wireless ERS within highways.

Figure 6 describes related cost associated with the development of wireless ERS in highways. However, the uptake of ERS will depends on the saving between the electricity cost per km and petrol/diesel (or biofuel) cost per km. Thus, an EV user will need to check the electricity price which is usually an aggregate of the “spot price + grid charges”, which ranges from 3.52 Euros to 7.04 Euros perkWh. In comparison to consuming diesel or biofuel (based on the current price) there may be difference in the breakeven level thereby favouring the use of diesel or biofuel in some conditions (Sundelin et al., 2018).

Irrespective of the potential of the different types of ERS solution for land transport electrification. There are still several safety issues that must be assessed as mentioned in the literature (Di Capua et al., 2016), ranging from potentially losses in wireless power transfer subsystems, safety against high chassis potential and touch current risks and/or risky cases in which a too high chassis potential could result in unsafe touch current levels for animals or people around the vehicle (Márquez-Fernández et al., 2019). Additonally safety regulations should be strictly adhered to road users and road owners. This relates to the risks regarding electrocution and the consideration of road workers safety especially during maintenance operations (Bateman et al., 2018). To help assess the safety issues associated with ERS, there is a need to adhere to electrical safety standards and risk assessment models (Wenander and Alaküla, 2024). For example electrical equipment should not be easily accessible to the public such as roadside equipment should be securely isolated to inhibit deliberate or accidental contact with potentially large electric currents (Bateman et al., 2018).

In wireless ERS the winding and contacting of the Radio Frequency (RF) strands to the capacitor board is part of the coil manufacturing process. High-precision positioning of the conductors is essential to minimize creepage distances in high-voltage areas. In wireless ERS the high-precision placement of the conductors is critical to reduce creepage distances in high-voltage areas. Also, safety measures such as insulation of the wire enamel as well as secondary insulation may be required to protect the Radio Frequency (RF) strands from each other (Wendt et al., 2024). An implementation of wireless ERS will require the installation of new infrastructure that can support the mobility of vehicles depending on the road traffic volumes (such as the vehicle kilometres per year in vkm/yr) and the type of ERS technology chosen (either overhead lines or electric rails/inductive supply (wireless)) (Taljegård et al., 2017). Besides, existing communication protocol implemented for wireless ERS needs to adapt for charging while the EV is in motion. As this is a challenge specifically in the transition between road segments covered by Wi-Fi access points. This necessitates some extensions for existing communication standards and definition required to support wireless ERS (Wendt et al., 2024).

There is also the challenge related to the planning and integration of wireless ERS in long-distance corridors. For example, how the wireless ERS can handle environmental conditions, such as harsh winter weather with high heating demand. This may require the vehicle to be charged to have sufficient reserve of energy termed as state of charge (SOC) of the battery which may be needed over the entire operation of the EV (Wendt et al., 2024). Findings from the literature mentioned issues related to the operation of wireless ERS infrastructure. This related to incidents or occurrence of partial or total power outages of charging infrastructure during the early phase of the ERS testing. Although this was addressed via software update, mainly to resolve internet outages. Also, in the onset of wireless ERS the average charging electric power was lower (lower voltage) than required. This also prompted fine tuning of communication channels and resonance frequencies for individual transmitter coils needed to improve the harvesting rate (Wendt et al., 2024).

Evidence from the literature indicated that the charging power from prior ERS was mainly lessened due to poor alignment of the vehicle with respect to the wireless charging infrastructure (Wendt et al., 2024). This challenge could be resolved by the provision of accessible driver training with incentives, electronic driving assistance systems, Heads-Up Displays (HUDs) or acoustic systems that provide guidance that aids better alignment with the wireless ERS infrastructure. Also, it will be helpful if existing wireless ERS be equipped with a higher misalignment tolerance (Wendt et al., 2024). Moreover, road administrative measures are being initiated to support wireless ERS area to be free from being blocked by parked non-EV (Wendt et al., 2024). The roll-out times has been mentioned as a factor that impacts how long a large-scale implementation of wireless ERS might be realistic for usage. This is because the planning, construction, and approval take times. Also, the time taken to construct a few km that enable wireless ERS will take a few years depending on the length of the road network (Plötz et al., 2024).

Another factor that influences wireless ERS is the connection for road intersections and road service that may influence general road service operations, and this depends on the type of ERS (such as in rail or catenary). There may be need to avoid contact with the electrical poles by large road service vehicles. Generally, there is need for having oversight of the electrical infrastructure needed for road administration (Plötz et al., 2024). The deployment of wireless ERS comprises of construction site logistics, civil engineering works preparation, coil installation, and asphalt road paving (Wendt et al., 2024). Where the durability and lifetime for building a wireless ERS analogous to railroad infrastructure, typically last at least 20 to 30 years (Plötz et al., 2024). Evidence from the literature (Sundelin et al., 2018), anticipated that the lifespan of an electrified road and electricity grid installation can usually last for about 40 years based on feedback received from the Swedish Transport Administration. Similarly, there was challenges related to the loss of network connection in the ERS negative rail. Where a conductive rail often consists of a positive rail and a negative rail (termed two-pole system) within the same track needed to provide a complete circuit for electric current transfer. Although this may not be applicable to wireless ERS, but it is important to be noted (Márquez-Fernández et al., 2019).

Discussion and implications

Transportation is the one of the main contributors of GHG emissions. Accordingly, findings from the literature (Brown et al., 2020), mentioned that the electrifying of road transportation via the electrification of vehicles has been highlighted as an important driver that reverse the impacts of climate change. Thus, recent advances in the development of EV technologies (e.g charging, energy exchange, etc.) are contributing towards sustainable transportation in highways (Schulte and Ny, 2018; Brown et al., 2020; Odoi-Yorke et al., 2026). Among these developments wireless ERS termed as dynamic charging using wireless or inductive coils installed in roadways would allow EV to be recharged and propelled (Ceravolo et al., 2016; Mathibedi et al., 2025). The implementation of wireless ERS can potentially support to reduce fossil fuel dependency (Sundelin et al., 2016; Jnr, 2024a), providing several benefits for the society, climate, and local environment (Gustavsson and Lindgren, 2020; Jnr, 2024b). The adoption of ERS help heavy vehicles reduce installed battery capacity to about 50–70% (Wenander and Alaküla, 2024).

Wireless ERS comprises of different subsystems such as electricity supply, road network, electric power transfer to EVs, management of daily road network operation and EV (Plötz et al., 2024). An optimum ERS network could either be constructed on specific road segments with EV only moving back and forth or along a major public road (Plötz et al., 2024). However, the deployment of wireless ERS is faced with different types of challenges that needs to be addressed for large scale development of ERS network within long-distance corridors (Ceravolo et al., 2016). Therefore, this study carried out a qualitative literature review to examine wireless electric road system for propulsion and charging of EV in highways. This study investigates key components and sub-systems needed to deploy wireless ERS for sustainable transportation in long-distance corridors. Also, this study identifies key factors that influence the deployment of wireless ERS for sustainable transportation in highways. Findings from this study provides implications for policy planning and regulations on the factors that influence wireless ERS infrastructure in long-distance corridors.

This study investigates electrification of the road transport sector, exploring how wireless charging could impact the electricity system of cities and communities. Analogous to prior studies (Brown et al., 2020; Plötz et al., 2024), this article suggests that the deployment of wireless ERS is complex as it needs to consider existing road network, energy grid, regional geography, local traffic, etc. Also, there is a need for policy revision and standardization processes that include both governmental and industrial representatives towards the deployment of ERS solution for the society (Plötz et al., 2024). Additionally, findings from this study present key stakeholders involved in ERS technology development and implementation, ERS technology policy legislation, and ERS technology acceptance and adoption. The findings also present the usefulness of wireless ERS and further identify factors as challenges, and potential application of wireless ERS for sustainable transportation in highways. Evidence from this study is analogous to findings from prior study (Brown et al., 2020), which highlighted that policymakers and governmental authorities can efficiently accelerate land transportation electrification through supportive regulations, tax incentives, and other policy tools (Brown et al., 2020).

Conclusion

Realizing widespread electrification of road transportation will require extensive expansion of the existing EV charging infrastructure (e.g., conductive and inductive charging networks), as well as upgrading of existing electric grids to support large-scale implementation of ERS in highways. Moreover, the adoption of ERS can contribute to reduce the need or large batteries in EVs with high cost, thereby accelerating the electrification and green transition towards sustainable road transport. While several studies have researched the potential of electrifying passenger transport, less emphasis has been on how road transport in highways could be powered in a sustainable future. Similar, although prior studies have explored ERS for conductive and inductive charging, there are fewer studies that extensively explored the feasibility of wireless ERS in highways. Accordingly, this article examines the factors that influences the deployment of wireless ERS and potential application of wireless ERS for sustainable transportation. More importantly this study explores the viability of wireless ERS to decarbonize road vehicles in highways. Grounded on secondary data from the literature findings from this article presents an overview of ERS, state-of-the-art of conductive charging, and applicability of inductive charging in ERS.

Additionally, findings from this article describes the operationalization of wireless ERS and key stakeholders involved in wireless ERS within highways. The findings further present three use cases and initiatives of ERS; rail-based solutions, overhead-line solutions, and wireless ERS solutions deployed with different regions. More importantly, findings from this article extensively identifies the factors influencing deployment of wireless ERS for propulsion and charging of EVs in highways. This study is faced with a few limitations; first only secondary data was employed in this article. The study intends to clearly delineate unique urban challenges such as lane-switching complexity, utility density, and frequent stop-and-go traffic as part of future works. Besides, study will be carried out to investigate how the wireless ERS scale for high traffic density in urban environments without performance degradation. Also, the identified factors that influence the deployment of wireless ERS was not validated. Thus, expert assessment or a more critical weighting of the identified factors would be investigated as part of future work. Lastly, the key components and sub-systems needed to deploy wireless ERS have not been implemented in highways. Future work will collect primary data to quantitively validate the identified factors. Beside the key components and sub-systems needed to deploy wireless ERS will be tested in a simulated environment.