In the late eighties Exin then owner of scalextric in Spain marketed a product known as STS (Super Track System)

The concept consisted of a 4 x 4 track with, bridges, steep hills, obstacles and Four-wheel drive vehicles.
Done at 1/48 scale the usual sets of the time included a track layout with the usual straights, curves, etc,
but also concave and convex track sections to make up either slopes or ridges in the road. Also reverse
gear was included on the throttle.

The vehicles were pretty peculiar in themselves, with the engine been mounted across the vehicle and a
continuous gear being used to power the wheels mounted under the vehicle.

Close up of Underside of Nissan Patrol

The whole thing was abandoned after some time (Probably when Tyco took production over)
and by the look of things it never really caught on.

This system was later followed by the TT system in 1/32 scale.