It'll play out in the opposite manner. The shift to EVs is going to happen first, followed by public transit. This is because EVs don't have a consensus / coordination problem. Electrifying a line or building a new line takes a minimum of a decade of planning, consultation, design and study, construction. But cars need replacement all the time and you can just go to a website and get an EV. Prices for batteries fall about 30% for every doubling of production. The spread of EVs is exponential, not linear. Sales roughly double every three years and many OEMs have stopped ICE development altogether. Once new car sales are close to 100% EV, existing stock will naturally die off.

Cars will electrify far faster than busses and trains in North America.