Many years ago when I was sharing a single car with someone who worked the complete opposite direction of me, I looked into the public transit thing. I lived in the west side of one city, worked in the east side of another. By car, it was 20-40 minutes depending on if you were in rush hour or not. While I would have hated it, 2x time commute by public transport would have been fine. But it wasn't even close.

I would need to walk a little over 2 miles to get to the nearest bus stop by my apartment, then I would need to take that bus into the downtown area, transfer to another bus to the central bus depot. From there I could pick up an "express commuter bus to a massive office park about half way between the two cities, where I would need to pick up another "express" bus to get to the next city. From there I would have to pick up another bus, which would take me luckily directly to my work place.

The problem was, none of these schedules were well coordinated. If I left around the time I would normally have to leave to make my shift on time, I would make it to my work place 6 hours later after accounting for all the waiting and transfer times. If I was willing to leave much earlier and arrive an hour before my shift (and if doing so met with the more frequent bus scheduling) I could get there in just 4 hours.

If you aren't directly on, and going almost exactly point to point for public transport outside big cities like NY, it can be so much worse than even "twice as long". I hated the wear and tear going all the way one way and then completely back across the cities the other way doing the shared commute required. I hated the sometimes hour or two wait before or after a shift to make the commute work with the other person. But using public transport was effectively impossible.