Most vehicles can drive under belts, pipes, and train ramps, but some require more clearance than others. When you hover over a vehicle's information in the vehicle depot, you will see its minimum required clearance. If no clearance is listed, the vehicle cannot drive under obstacles. In that case, the only way for it to cross pipes or belts is by using a {0}.
{0} = Ramp
It is translated as: ... by using a Vehicle ramp (small).
Since there are 3 dimensions for the ramps, specifying the dimension in the tutorial example is misleading.
A generic term for "Ramp" (singular) is needed.
Or perhaps you should match "Ramp for vehicles," that already exists.