For motor vehicles: Downforce. toe, camber.
Added: For railroad trains - the steel flanges on the wheels that travel along the inner surface of rails prevent the cars from leaving the tracks.
No. Dolphins do not leave tracks.
Rail tracks
she hates you
See the Related Link(s) below.
It keeps the tracks the same distance apart.
That's unknown ... tracks to guide cars were around long before railroads were invented.
They both travel on tracks.
For an engine to run on the tracks without any cars.
Gravity and friction.
The odometer
The train tracks - however the fact that the tracks are frozen has little or nothing to do with the operation of trains, unlike the effect on traction for cars and trucks.
The wheels are on top, between and below the tracks.