The subway has tires for technical reasons. Stations in the Paris subway are close enough that better acceleration times have a significant impact on travel time and peak-hour capacity.

If they were willing to retool, you’d think they’d just go with a maglev monorail design. Those have the capacity for the instantaneous acceleration of a railgun.

That would be a pretty rough ride. I wouldn't want to be a straphanger on one of those. The turns would be uncomfortable as well in a railgun railway car.

It would also be useless, the stations are so dense that you would barely increase the average speed.

I didn’t mean to suggest you’d use it as a railgun. It just has the capacity for exactly as much torque as you need from it at any given moment.

Maybe the study should also take into account this use of tyres.