30. Network Rail must, on receipt of a request from the Council, from time to time provide the Council free of charge with written estimates of the costs, charges, expenses and other liabilities for which the Council is or will become liable under this Part of this Schedule (including the amount of the relevant costs mentioned in paragraph 29) and with such information as may reasonably enable the Council to assess the reasonableness of any such estimate or claim made or to be made under this Part of this Schedule (including any claim relating to those relevant costs).