All wireless chargers are inefficient and there isn’t a known way to make them efficient. There are some theoretical things you could do, like beam steering of the EM field so that more of the energy intersects with the receiving coils, but in practice that’s so insanely expensive as to be fantasy for something as large as a roadway. The efficiency will also never be as good as running the current through a wire.
All wireless chargers are inefficient and there isn’t a known way to make them efficient. There are some theoretical things you could do, like beam steering of the EM field so that more of the energy intersects with the receiving coils, but in practice that’s so insanely expensive as to be fantasy for something as large as a roadway. The efficiency will also never be as good as running the current through a wire.