If you needed to transfer this data particularly far. Say from Alaska to Argentina (Practically to the the other side of the world) you would need to drive pretty fast to beat ISDN. One guy did this route as a road trip and documented it taking 23 days.
But if you didn't have ISDN and had to do it with 56K dialup modems it would take at least 3 times as long so it would now take about 1/4 of a year to complete. Dialing directly would probably also cost more than actually driving your truck there.
You could get in a plane with a backpack full of 2-4 GB drives or a bunch of tapes... maybe 2 days max with mixing with trains and ferries and cars...
You could even argue it's cheaper depending how much in advance you could reserve tickets for cheaper price.
Here in Romania when dial-up was still a thing and isdn barely started, isdn was... probably 200-300$ a month in today's money.
You could bribe a train driver or the guy that checks tickets on train with 5-10$ to take a package and deliver it in hands of guy waiting at station...
6-8h and your package is across country (~300-400 miles)
Parents do this for university students even now... cheaper than regular mail and faster.