The achievement unlocked for me having found 120 – 123 fast travel dataterms.
There is at least 130 + fast travel dataterms throughout Night City.
You do not need to interact with them for them to count. You just need to drive in the vicinity of each for them to count and they will show on your mini map. All can be found without leaving your vehicle.
* If your achievement tracker gets stuck, interact with one of the fast travel dataterms and back out. Doing this should fix the achievement tracker.The locations of 130 + fast travel dataterms can been seen below: