6. In this Act—
“the Department” means the Department for Regional Development;
“operator”, in relation to a railway, means a person carrying on an undertaking which includes that system of transport, or the provision of transport services on that system;
“railway” means a system of transport employing parallel rails which—
provide support and guidance for vehicles carried on flanged wheels; and
form a track which is of a gauge of at least 350 millimetres;
“vehicle”, in relation to a railway, includes anything which (whether or not it is constructed or adapted to carry any person or load) is constructed or adapted to run on flanged wheels over or along parallel rails.