83Similarly, the application of other provisions of Directive 2001/14 require that infrastructure managers be allowed some degree of flexibility, in order to encourage them to optimise use of their infrastructure. Indeed, Article 8(2) of the directive provides that the infrastructure manager may set or continue to set higher charges on the basis of the long-term costs of certain investment projects. Article 9 of the directive permits the infrastructure manager to introduce a system of discounts on charges levied by operators.