What tower-level accuracy actually means
This is the number to understand before deciding whether SIM tracking solves your problem, and it is the one most likely to be glossed over.
A GPS device fixes position from satellites and reports a few metres. SIM tracking infers position from the cell tower currently serving the phone, so the answer is as precise as that tower’s coverage area.
In a dense city with towers close together, that can be a few hundred metres. On a highway or in a rural stretch where one tower covers a wide area, it can be several kilometres.
So it answers "which town is the vehicle near, and is it moving in the right direction". It does not answer "which gate is it standing at" or "did it stop for forty minutes at that dhaba". If your question is the second kind, you need a device.