Under road charging does sound like a huge undertaking but roads regularly get pulled up for resurfacing or expansion. The main road near my place has had some part of it involved in road works, almost continuously for many years. The charging infrastructure could have been put in many times over with no additional disruption to traffic. Many of these major roads already have high capacity electrical connections installed all down their length. Used for the lighting that shines all night even when the road is empty.
Concerns over non-electric vehicles getting fried as they roll over the charging pads are unfounded. Your electric car would communicate with the charging pad. Negotiating charge parameters. Checking you bank balance etc.
Only then would the charge pad activate. Timed to deliver the charge as precisely as possible. Other cars would just be driving over an inert piece of technology.
This sort of communication already occurs for automatic payment of road tolls.
Oh and you wouldn't need 15 minutes of roadway converted to charging. I believe the charging units would only be several meters long and spaced nearly a kilometre apart.
Some sort of super capacitor set up would take a large amount of power in the short time the car was above the charging pad. Then it would deliver it at a lower rate to the electric motor. Enabling the car to travel to the next charging pad and beyond. Any excess or unused power would be used to top up the batteries. So more a pulsed charging rather than the constant charge you would get from a fixed charge point or a domestic power supply.
Oh and i recently watched the Rob Llewellyn video "Electric Cars Are Rubbish. Aren't They?"
https://youtu.be/6q7_xN0ilag?t=2607
I know, i know, not the most authoritative information source and it may also have given me a slightly jaded view of hydrogen cars.
I nearly fell off my chair when he said $250000 dollars just for the fuel cell in the Honda Clarity. Improvements in technology may be able to reduce this. Economies of scale will help as well but unless they can reduce the platinum required then it will stall, platinum isn't likely to have a ten fold drop in price.