A Road Deviation is a change in the location of a road reserve. Road deviations may be necessary for a number of reasons. One example would be where the appropriate horizontal road alignment for a given design speed can not be fitted within the existing road reserve.

Victoria
In Victoria Clause 2 of Schedule 10 of the Victorian Local Government Act 1989 gives Councils the power to deviate roads.
It states that:
(1) A Council may deviate a road through private land, Crown land or land held by licensees under the Land Act 1958 (whether or not the land is subject to any rights of way).
(2) However, in the case of a proposed deviation—
(a) through Crown land; or
(b) which would result in the vesting of land in a Council under section 207B(2A)— this power may only be exercised after the Council has obtained the consent of the Minister administering the Land Act 1958.
(3) Before starting any work to give effect to a deviation, the Council must publish a notice in the Government Gazette describing the deviation.