How to control electric bus by underground wire ?

Hi,

how to guide electric bus by underground wire , using metal or Hall detectors to calculate the correct drive path, direction to match overhead power lines ?

In the following video, electric trolleybus model is driven by overhead line and drive direction path follows overhead power lines

Eheim Trolleybus (2 min 13 sec)

Since my kids car turned trolleybus is much heavier, I cannot use overhead power lines as a guide to drive path, so I need to bury
another wire in the ground and use metal detectors or Hall detectors to follow the correct track to draw energy from overhead lines.

Any idea ?