One of the concepts include embedding electrical coins underneath the road, and while this might be the more elegant solution, it would be expensive and time consuming as it would require the roads to be torn up. Other solutions developed involved transmission coils and receiver coils, with one larger than the other, but the resulted in safety concerns, complexity, and would be expensive to build as well. What the scientists have done is found some kind of happy middle where the transceiver and receiver coils are of the same size.
The system will be able to detect when a receiver is within range, and when it is, it will ask the transmitter to output 400% more power, and when no receivers are around, it will emit a safe and low-level electromagnetic field, which hopefully should allay the concerns of those worried about electromagnetic radiation. At this point in time this is merely a proof-of-concept, so there’s really no telling if and when such a system would be put into place.