Land bridge in RollerCoaster Tycoon 3 demo?

Okay, it took me a while to find out how to build stairs from a higher path
to a lower path (point at the end of the higher path to trigger the next
path ghost, then hold down the left mouse button and move the mouse down
until the path gost turns into a stair gost).

However, how do I build a land bridge from ground level? This was obvious in
RCT2 as it is done sort of like building tracks, but I have no idea how to
do this in the RCT3 demo and I would like to build a bridge over
obstructions (e.g. coaster tracks, train tracks, station in the way) when I
need to.