About this article
This article highlights groundbreaking research led by Associate Professor Yudai Honma at the University of Tokyo, revealing how cities can enable “infinite driving” for electric vehicles with less than 1.6% of streets equipped with in-motion wireless charging (DWPT). Using advanced optimization and real-world traffic simulations in Kawagoe City, the study shows how small, strategic stretches of in-motion wireless charging, placed where vehicles naturally slow or stop, for example at traffic lights, can keep EVs powered continuously. The article also explores how Electreon’s wireless charging ecosystem aligns with this research and offers cities a practical, elegant pathway to cleaner, smarter, and even autonomous-ready electric mobility.
Just 2.4 km of a 150 km road network can power a whole city
Electric vehicles promise cleaner, smarter cities—but only if we clear the key roadblocks holding widespread EV adoption back: range anxiety, long waits at chargers, and the simple truth that most people don’t want to map out their day around plugging in.
That’s why new research from Associate Professor Yudai Honma at the University of Tokyo is such a breath of fresh air. His team introduced a bold but beautifully simple idea: what if EVs could charge while they drive? Using DWPT—Dynamic Wireless Power Transfer, a technology that sends energy from coils in the road to receivers in the vehicle—EVs can top up on the go, reducing charging stops and making driving feel truly effortless.
And here’s where it gets even better: the team showed that cities don’t need chargers everywhere to make this happen. In fact, equipping less than 1.6% of city streets with DWPT—placed where vehicles already slow or stop, like intersections and bus stops—can keep EVs powered continuously. To put it in perspective, in a modeled city with nearly 150 km (93 miles) of roadway, that same fraction amounts to only about 2.3 km (∼1.43 miles) of cumulative wireless charging stretches—strategically placed to let EVs move throughout the city without ever waiting to charge. It’s a striking reminder that small amounts of smart infrastructure can create a city where charging simply disappears into the drive.
The big question and the clever system built to answer it
Prof. Honma’s team didn’t just wonder whether a city could run on wireless roads powered by DWPT—they built a sophisticated two-part system to find out.
First came a massive mathematical optimization model that divided the entire city of Kawagoe into more than 21,000 tiny segments, each just 7 meters (23 feet) long. Every segment became a simple yes/no question: should wireless coils go here or not? The model then searched for the smallest installation footprint that could power every EV across all routes, speeds, and stop-and-go conditions—serious computational muscle usually reserved for airline scheduling and global logistics.
Then came the high-resolution traffic simulation, the heartbeat of the study. Instead of assuming neat, predictable traffic, the team modeled real-world movement: fluctuating traffic volumes, changing light patterns, queues forming at intersections, moment-to-moment acceleration and braking, and all the little crawls, pauses, and surges that make a city feel alive.
By combining these two systems, the researchers could identify not just where EVs travel, but where they linger—and therefore where DWPT would deliver the biggest impact.
With the model fully assembled, all that remained was to choose the perfect real-world testbed.
How 1.6% of electrified streets enables continuous EV driving
Kawagoe City—a suburb of Tokyo with about 350,000 residents, roughly the size of Cleveland or Florence—proved to be the ideal real-world test bed for an ambitious question: Could all the EVs in a city—both fleets and everyday passenger cars—drive indefinitely without ever stopping to charge?
The answer was astonishing. The model showed that Kawagoe would need only about 2.3 km (∼1.47 miles) of wireless charging—spread across 56 strategic intersections—to keep every EV moving continuously. That’s just 1.6% of the city’s road network, placed exactly where vehicles naturally slow or stop, for example at traffic lights. These short segments boost energy transfer, cut installation costs, and match real traffic behavior with remarkable accuracy.
And the insight held strong under pressure. The researchers ran dozens of sensitivity tests—changing traffic demand, shifting light timings, tweaking routes, and adding congestion—and even with all these factors combined, the overall result remained essentially unchanged.
In short: infinite driving is real, repeatable, and surprisingly attainable.
This strong work earned the study a spot at the 2025 Transportation Research Board (TRB) Annual Meeting, underscoring it as a genuine breakthrough—not just a clever simulation.
What cities everywhere can do with this insight
This research flips the script on city electrification. Instead of building oversized charging networks or carving out space for endless parking-lot chargers, cities can focus on the specific spots where vehicles already slow or stop—and unlock smooth, continuous electric mobility.
Imagine Amsterdam electrifying buses without massive batteries, Los Angeles shrinking its charging queues instead of adding more charging hubs, or London boosting air quality without digging up half the city. Even grid operators benefit, because wireless roads distribute power gently and predictably rather than creating messy charging spikes.
It all comes down to a wonderfully simple idea: cities don’t need chargers everywhere—just in the smartest places.
And that’s exactly where Electreon enters the story.
Wireless charging built for an autonomous future
Electreon’s wireless charging ecosystem aligns closely with Prof. Honma’s findings—especially around high-value slowdown points. Electreon DASH delivers powerful opportunity-charging bursts where vehicles naturally decelerate or pull away, such as intersections, bus stops, and stop-and-go queues. Electreon DOT tops up vehicles at parking lots, mobility hubs, and end-of-route stops. Electreon LINE energizes vehicles along the road, allowing them to charge while driving.
Together, these components create a seamless, cable-free charging system that mirrors the model’s strengths: powering vehicles through the natural rhythm of movement, keeping batteries smaller and longer-lasting, smoothing grid peaks, and enabling continuous, worry-free operation for fleets and everyday passenger cars alike. And because charging happens automatically within the flow of traffic, the system is perfectly suited for a driverless future—where vehicles need to stay powered without human intervention.
And the best part? It all works by electrifying only the most strategic spots in the city, creating a simple, elegant path to electrification that cities can adopt right now.
Curious what wireless charging could look like on your streets? Reach out and let’s map it out. Contact us today.
FAQs
What exactly is DWPT?
DWPT (Dynamic Wireless Power Transfer) is a technology that charges electric vehicles while they drive. Energy is transferred from coils embedded in the road to receivers under the vehicle—no cables, no plugs, no stops.
How can less than 1.6% of streets power an entire city’s EVs?
Because the wireless segments are placed in high-impact locations—intersections, slow-down zones, and bus stops—where vehicles naturally spend time. These brief moments are enough to keep batteries topped up.
Why was Kawagoe City used for the study?
Kawagoe has dense, complex traffic patterns and around 150 km (93 miles) of roads—ideal for testing how DWPT performs in a real, busy urban environment.
Does this work for both private cars and fleets?
Yes. The model covers all vehicle types—buses, trucks, taxis, and everyday passenger cars—showing continuous, stop-free driving is possible across an entire city.
How does this connect to Electreon’s technology?
Electreon already builds DWPT systems (LINE, DASH, and DOT) that match the study’s highest-impact areas. Together, they enable smooth, cable-free charging that supports today’s EVs and tomorrow’s autonomous mobility.