The fixed installment system of depreciation is adopted wherein a fixed percentage determined with reference to probable future life of the fixed asset is written off each year. The rate of depreciation and the estimated life of the assets are determined by the Govt. of India. On the basis of the formula an amount is transferred to the Depreciation Reserve Fund.

Expenditure on replacement of a worn-out asset is, with the concurrence of the Government, and to the extent of the amount lying in credit of that asset is met out of the Depreciation Reserve Fund.

The entire cost of services of Lighthouses and Lightships is met out of the receipts realised from light dues. An excess of the receipts over the revenue expenditure is transferred to the General Reserve Fund. Capital expenditure subject to availability of funds is also met out of the reserve.

Both the above mentioned funds are maintained by the Department of Lighthouses and Lightships. These are interest bearing funds. Interest calculated on the basis of fixed formula it treated as Miscellaneous Receipts of the Department and is not created to these funds.

A fee is levied on mechanically propelled vehicles using permanent bridges on National highways, which cost more than Rs.25 lakhs and were built and opened to traffic on or after 1^st April, 1976. The proceeds collected from States and Union Territory Govts. Are initially created to the Consolidated Fund of India. These are transferred to National Highways Permanent Bridges Fee in the Public Account of India out of grants voted by Parliament. Collection charges payable to State Govts. And UTs are also made of this fund by way of grant voted by Parliament. The balance in the fund is utilised for development of National Highways.