15) raudteeinfrastruktuuri arendamine on raudteevõrgustiku kavandamine ning raudteeinfrastruktuuri finants- ja investeeringutealane kavandamine, rajamine ning ajakohastamine ehk olemasoleva raudteeinfrastruktuuri ulatuslik muutmine, mis parandab selle üldist toimivust;, 15) development of railway infrastructure means the planning of railway network as well as the financial and investment planning, construction and modernisation of railway infrastructure, i.e. extensive modification of the existing railway infrastructure to improve its overall functionality;, defineeritakse selle seaduse ulatuses, defined within the scope of this Act