Of course, but rollercoasters also frequently have much more money to spend on security features, so technology first seen there shows up a while later in publi

Of course, but rollercoasters also frequently have much more money to spend on security features, so technology first seen there shows up a while later in public transit. E.g., modern signalling that replaces the old block signalling, or the station door systems to let people in/out which now are also in major subways around the world.